This is a model from the G-Shock Mudmaster Series, designed for use in extreme environments scattered with rubble, dirt and debris, and uses carbon materials. The use of high rigidity carbon on the case keeps damage and deformation at bay, and ensures a high level of airtightness and shock resistance. This model also features a filter that protects against the invasion of mud, a stainless steel panel back, and a back cover made of shock-resistant fine resin embedded with glass fibers, giving it a high level of resistance to dust and mud. The bezel also uses three layers of fine resin with carbon fiber inserts and is designed to resemble a portable gasoline can that could be found on off-road vehicles. Function-wise, this model comes with compass, altimeter/barometer, temperature reader and pedometer. In addition to being able to easily correct the time using the dedicated CASIO WATCHES app, there are lots of other useful features including the Mission Log feature, which automatically records in the app altitude data obtained from the watch and route data obtained by your smartphone. This is a toughness watch that supports you in taking quick decisions and accurate actions.
This is a model from the G-Shock Mudmaster Series, designed for use in extreme environments scattered with rubble, dirt and debris, and uses carbon materials. The use of high rigidity carbon on the case keeps damage and deformation at bay, and ensures a high level of airtightness and shock resistance. This model also features a filter that protects against the invasion of mud, a stainless steel panel back, and a back cover made of shock-resistant fine resin embedded with glass fibers, giving it a high level of resistance to dust and mud. The bezel also uses three layers of fine resin with carbon fiber inserts and is designed to resemble a portable gasoline can that could be found on off-road vehicles. Function-wise, this model comes with compass, altimeter/barometer, temperature reader and pedometer. In addition to being able to easily correct the time using the dedicated CASIO WATCHES app, there are lots of other useful features including the Mission Log feature, which automatically records in the app altitude data obtained from the watch and route data obtained by your smartphone. This is a toughness watch that supports you in taking quick decisions and accurate actions.
This is a model from the G-Shock Mudmaster Series, designed for use in extreme environments scattered with rubble, dirt and debris, and uses carbon materials. The use of high rigidity carbon on the case keeps damage and deformation at bay, and ensures a high level of airtightness and shock resistance. This model also features a filter that protects against the invasion of mud, a stainless steel panel back, and a back cover made of shock-resistant fine resin embedded with glass fibers, giving it a high level of resistance to dust and mud. The bezel also uses three layers of fine resin with carbon fiber inserts and is designed to resemble a portable gasoline can that could be found on off-road vehicles. Function-wise, this model comes with compass, altimeter/barometer, temperature reader and pedometer. In addition to being able to easily correct the time using the dedicated CASIO WATCHES app, there are lots of other useful features including the Mission Log feature, which automatically records in the app altitude data obtained from the watch and route data obtained by your smartphone. This is a toughness watch that supports you in taking quick decisions and accurate actions.
This is a model from the G-Shock Mudmaster Series, designed for use in extreme environments scattered with rubble, dirt and debris, and uses carbon materials. The use of high rigidity carbon on the case keeps damage and deformation at bay, and ensures a high level of airtightness and shock resistance. This model also features a filter that protects against the invasion of mud, a stainless steel panel back, and a back cover made of shock-resistant fine resin embedded with glass fibers, giving it a high level of resistance to dust and mud. The bezel also uses three layers of fine resin with carbon fiber inserts and is designed to resemble a portable gasoline can that could be found on off-road vehicles. Function-wise, this model comes with compass, altimeter/barometer, temperature reader and pedometer. In addition to being able to easily correct the time using the dedicated CASIO WATCHES app, there are lots of other useful features including the Mission Log feature, which automatically records in the app altitude data obtained from the watch and route data obtained by your smartphone. This is a toughness watch that supports you in taking quick decisions and accurate actions.
Last updated at 05/11/2026 19:20:41
Casio G-Shock GST-B100D-1AJF Steel 53.8mm
Delivery $136
Casio G-Shock GST-B100D-1AJF Steel Black
Delivery $36
Casio G-Shock GST-B100D-1AJF Steel
Delivery $43
Casio G-Shock GST-B100D-1AJF
Delivery $43
Casio GST-B100D-1AJF
Free delivery
Casio G-Shock GST-B100D-1AJF Steel Black
Delivery $36
Casio GST-B100D-1AER
Free delivery
Casio G-Shock GST-B100D-1AER Steel Black 50mm
Delivery $67
Casio G-shock G-steel Gst-b100d-1ajf Bluetooth Tough Solar Black Dial
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
Casio G-shock G-steel Gst-b100d-1ajf Black Silver Men's Watch Analog
Free delivery
Affiliate Disclosure: We may receive a small commission for purchases made through this link at no extra cost to you. This helps support our site. Thank you!
originally posted on H.Samuel - The Jeweller
This is an incredibly tough yet attractive looking watch and is not for the faint hearted! Yes, it's certainly chunky but not overly heavy or bulky on the wrist and looks really girl with its architecture. It has Bluetooth where you can set differing time zones, an alarm as well as a phone finder even if your phone is on mute. It also hunts for a time transmitter in order to reset time to the micron. I found the initial set-up quite complicated but after emailing Caso, they phoned me the next day and talked me through the set-up procedure and all is well. A great watch at a great price that I found on H. Samuel’s website so go buy one now! I needed a bracelet adjustment which was ably done by Becca at the Kingston-upon-Thames branch of H. Samuel. Regards Malcolm D
originally posted on ebay.com
I have always had a Casio on my wrist. My one complaint has always been their accuracy. The GST B100 solves that by synchronizing with your cell phone 4 times a day. I especially like the LED night light. I also find the dial very easy to read.
originally posted on g-shock.co.uk
Having owned G Shock, Pro trek and heaps more Casio watches.I wanted something different.Bluetooth works well in setting up the time and keeps it at a pin point accurate time piece.Comes with Timer, stop watch, world time (2) cities LED Light is fantastic.Very comfortable fit and a large wrist watch too. Dressy and casual look about it.20 bar depth. Solar powered and the G Shock status.Fantastic purchase at a fantastic price.Not dissapointed at all.
| Diameter | 53.8 mm |
| Water Resistance | 20 Bar (Dive) |
| Time | hours - Analogue hand |
| Calendar | Date - Window |
| Chronograph and timers | Stopwatch /Chronograph - Add and split functions |
Casio G-Shock GST-B100D-1AJF Steel 53.8mm
Delivery $136
Casio G-Shock GST-B100D-1AJF Steel Black
Delivery $36
Casio G-Shock GST-B100D-1AJF Steel
Delivery $43
Casio G-Shock GST-B100D-1AJF
Delivery $43
Casio GST-B100D-1AJF
Free delivery
This is an incredibly tough yet attractive looking watch and is not for the faint hearted! Yes, it's certainly chunky but not overly heavy or bulky on the wrist and looks really girl with its architecture. It has Bluetooth where you can set differing time zones, an alarm as well as a phone finder even if your phone is on mute. It also hunts for a time transmitter in order to reset time to the micron. I found the initial set-up quite complicated but after emailing Caso, they phoned me the next day and talked me through the set-up procedure and all is well. A great watch at a great price that I found on H. Samuel’s website so go buy one now! I needed a bracelet adjustment which was ably done by Becca at the Kingston-upon-Thames branch of H. Samuel. Regards Malcolm D
I have always had a Casio on my wrist. My one complaint has always been their accuracy. The GST B100 solves that by synchronizing with your cell phone 4 times a day. I especially like the LED night light. I also find the dial very easy to read.
Having owned G Shock, Pro trek and heaps more Casio watches.I wanted something different.Bluetooth works well in setting up the time and keeps it at a pin point accurate time piece.Comes with Timer, stop watch, world time (2) cities LED Light is fantastic.Very comfortable fit and a large wrist watch too. Dressy and casual look about it.20 bar depth. Solar powered and the G Shock status.Fantastic purchase at a fantastic price.Not dissapointed at all.
This is a great watch! For its' size---it dominates my wrist---it is very light weight. I am still learning the various features but , so far, my favorite feature is the large white hands on the black background. A quick glance (as opposed to reading) is all it takes to know the time. I am sure it will become more impressive over time but so far it is very much liked. I highly recommend this watch.
Great watch very pleased with first class watches. Fast posting, delivered within 2 days of ordering. Good website and watch is exactly as described. Nice big bracelet had to remove 2 links, and my wrist isn’t small.Once the Casio app is downloaded, setting the time is simple using my phone, not the watch! Amazing. Great watch, easy to use, built to last, forever.
I like the watch, great design, easy to set up everything using Bluetooth on your phone, but I would suggest to avoid setting the time, day, month and year manually, it's really inconvenient and confusing at the first sight. Even when you need to set the timer quickly, it's just uneasy, because using the crown is time consuming and unhandy. If you need something more functional where you can use timer and stopwatch easily it's better to choose mudmaster in this price range. Another minus is that you cannot turn off the sound when pressing buttons or maybe I just haven't found out yet.
I am very impressed by the service value and peace of mind that First Class Watches provide .i am happy to recommend them to my friends and family.The communication, shipping speed and price including shipping is the most competitive if all other sellers .The G Shock Steel is a really stunning timepiece perfect working functions great contrast of steel and resin already getting compliments and being asked where i bought it from and were suprised at the excellent value .G Shock Steel GST B100Overall a great smooth and easy transactioni will be buying more from them for gifts and for myself in the future .I would give 6 stars !Best regards to all at First Class Watches.Thanks againHarry .
After such a positive experience with the purchase of the GSTB200D though Rowland of first class watches I just had to come back again.The GSTB200D was the most beautifully, well engineered watch I had ever laid eyes on until now that is, when I held in my hand the GSTB100D!The watch screens luxury and tank tough at the same time. Being fully analogue it is similar and yet completely different to it's ana digital brother..Do I favour one over the other? Just purchase both..As expected the watch arrived in record time (5 days) in exceptional packaging. The service I received from Rowland was first class and was the main reason for me coming back for more so early on in the piece...Thanks again fellas... A job well done indeed!Now for what G to buy next.....
Great watch. Solar powered with 6 month battery life with full charge. Multi band six so picks up atomic signal from Colorado to set the time. Backlight is amazing on this model -- it is blue in color and lights up the back portion of the dial and the main white ticks at one, three, five, seven, nine and eleven. This also lights up the hands of the watch with very bright green edges on the hands. The hands also glow in the dark along with small ticks at each of the numbers on the dial. G-Shock protection, water resistant to 200M and mud resist. Black case with gray band. Very heavy duty. Hourly chime, 5 alarms, world time, stopwatch and timer. Super cool watch. MSRP from Casio tag is $300.00 USD.
Love having a watch that keeps perfect time, due to blue tooth connection with phone. Also no need to replace batteries as is solar charged. A jolly good purchase and the seller was good enough to send me parts of the strap to enlarge it. A smashing experience overall.
| Diameter | 53.8 mm |
| Water Resistance | 20 Bar (Dive) |
| Time | hours - Analogue hand |
| Calendar | Date - Window |
| Chronograph and timers | Stopwatch /Chronograph - Add and split functions |
