Save Water: Water your garden from anywhere when needed. Equipped with a proprietary Zigbee protocol, it provides wider, more reliable wireless coverage than Wi-Fi Easy to Set Up: Save yourself the headache of a complicated and costly installation. No electrician is required to install the LinkTap sprinkler controller since it is powered by 9-volt batteries Flexible Power Options: One LinkTap Gateway can control up to 15 LinkTap watering devices (smart sprinkler controller, wireless water timer) simultaneously Flexible Configuration: One LinkTap Gateway can control up to 15 LinkTap watering devices (smart sprinkler controller, wireless water timer) simultaneously Powered by one or two alkaline, lithium, or rechargeable lithium 9-volt batteries (not included), the LinkTap wireless sprinkler controller (a.k.a. ValveLinker) can operate most mainstream DC latching 3-24V solenoid valves (1/2", 3/4", 1", 1.5", 2", etc.). In many cases, the ValveLinker can be a drop-in replacement for existing battery-powered irrigation controllers. Additionally, complemented by the LinkTap 1" flow meter (optional, sold separately), the ValveLinker is able to measure flow rate and volume in real-time for each zone. With the supplied fixings, the ValveLinker can be conveniently hung on a wall, hung or left standing on a hardwood stake, or placed in a valve box. The ValveLinker uses the same LinkTap Gateway and app as the LinkTap wireless water timers. If you already own a LinkTap system and are thinking to expand it, you can just get the add-on ValveLinker. Save your investment! For first-time buyers, a LinkTap Gateway is required. One LinkTap Gateway can control up to 15 LinkTap watering devices (i.e., ValveLinker, wireless water timer) simultaneously. Important: The ValveLinker can only operate 3-24V DC latching solenoids; it CAN NOT drive any type of AC solenoids, nor can it control semi-direct lift solenoid valves.