This muscle fascia gun is designed with premium metal housing and super powerful brushless motor, delivering high penetration, rejuvenating sore tissue and aching muscles. - Ultra – Portable & Silent for Back Workout Athletes: Weighted only 1.5lbs, this deep tissue muscle sport massager is ultra compact and easy to grip. A super quiet brushless motor, as low as 45d - B, makes it ideal for home, office or gym use! Up to 3200rpm(5 Speeds) & 5 Massager Heads: 5 speeds from 1800 to 3200rpm are provided for different muscle groups, aiding in sore muscle relief, relax and shape different muscle parts. Choosing from 5 different shaped massager heads, power on the device, you can start to relax your body parts.2500m - Ah Long Battery Life & 10 minutes Auto – Off Protection: The muscle massage gun is equipped with a rechargeable 2500m - Ah high – quality lithium battery, and it can power a weeks’ worth of workouts after fully charging. 10 – minute auto – off feature for safety consideration. - Convenient USB Charging Machine – No worry about charging when you travel with it in different countries. This deep tissue percussion muscle massager can be charged by USB with the regular phone adapter or 5V/2A adapter, and can be charged by power bank too.