Designed with powerful floating action to provide a positive message through the fingertips scalp, face and neck, built for years of trouble-free Service, can be run for long period of time without overheating. How to attach to hand: With the palm of hand down, insert all FOUR FINGERS into the rear spring strap. Either hand can be used. Insert the two middle fingers only into the front spring strap. Push machine back on hand so that the front small rubber pad transmits the vibration to these fingers.