Hyperice Vyper Vibrating Foam Roller - One - Pink High Intensity - Engineered to deliver high intensity and high frequency vibration into the body. 3 Speed Setting - All digital circuitry controls 3 speed settings. Eco-Friendly - Eco-friendly, German-made outer shell transfers maximum vibration. Rechargeable Batteries - Rechargeable lithium on batteries give over 2 hours of use per charge. Charger - Vyper AC charger included.