Features: Used to relax muscles, relieve stress and improve the circulation. Adopts brushless motor and high-quality bearing for an almost drop-dead silent massage. Interchangeable massage-heads in 8 shapes to target specific muscle groups for faster recovery. Specially designs 22 levels of speed adjustable, you can adjust it according to your need. 3200r/min rotation rate brings 10kg impact force, effectively decomposing lactic acid. Equipped with memory function, it would switch to the level that you use last time automatically. Short circuit and overload protection, prompt response of instructions. USB Charging, supports connect to power-adapter, notebook, portable source, ect. Large capacity lithium-battery has long endurance time. Comes with a portable travel case to keep all the parts in perfect order, making it easier to store. Specifications: Material: ABS + rubber Color: black, green ,optional, Rated input: 100-240V, 50/60Hz, 24W Rated output: 8.4V/1A Vibration level: 22 levels Amplitude: 12mm Rotation rate: 1800-3200r/min Endurance time: 3h Power supply: built-in lithium-battery Battery-capacity: D C 7.4V/1800mAh Item size: 230 * 210mm / 9.05 * 8.27in Package size: 350 * 250 * 95mm / 13.78 * 9.84 * 3.74in Package weight: 1437g / 3.17lb Note: Due to the different display screen and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Package List: 1 * Muscle Massager 8 * Replaceable Massage-Heads 1 * Charging Cable 1 * Storage Case 1 * User Manual