ReJu is a low frequency electrotherapy device that relieves the stiffened muscle and muscle pain by delivering a specific rhythmic electric stimulation to the nerves and the muscles through an electrode attached to the skin. Compared to other products, our product is well-designed, wireless and easy to carry. Both standard type and butterfly type electrodes can be attached anywhere on the body and go anywhere at convenience. ReJu has four different modes and 15 power levels. Battery is re-chargeable with USB cable. These are the big strengths compared to other products.