Textured silicone outer. Features: Low surface area pinpoints pressure for focused treatment, 3 customizable vibration frequencies, QuietRoll Technology mutes reverberation, Smart device with Bluetooth® connectivity, 120-minute battery life, Innovative wave texture for max traction. Includes: Protective carrying pouch, USB-A to USB-C cable. Diameter: 8.6cm. Battery life: 200 minutes. Warranty: 2-Year Limited Warranty.