Tens Unit Electrotherapy Machine Dual Channel Rechargeable Pain Relief DeviceFeatures Multiple functional preprogrammed 24 different massage modes for Pain and Muscle Relief. A B Dual Channels with 24 Modes, 20 level Intensity, and Time Control. relax Any Time Anywhere with Pocket Size! it can be used in the office, car, or travel on the go. Total body relaxation: use for the back, knee, shoulder, ankles, wrist, and elbow and make this the most powerful weapon for your body to relax. Tens Ems Combo You can use either Tens