Features1. Use it Anywhere: This TENS unit massager machine relieves lower, mid, and upper back pain from sciatica, arthritis, muscle tension, inflammation, and injury by delivering nerve stimulation through gentle electrical pulses.2. 8 Modes and 19 Intensity Levels: The tens-unit muscle stimulator provides 8 modes and 19 intensities to meet different needs. The 15-minute auto-off feature automatically turns off when you're on the go, preventing overtreatment.better for back, neck, leg pain.3. Built-In Powerful Rechargeable Battery: The wireless tens unit muscle stimulator for pain relief therapy can be easily powered by any wall chargers, power banks, laptops and USB adapters. Built-in batteries provide long-lasting power for a variety of purposes. 4. Your Best Tens Unit Pulse Massager Choice: Looking for a way to maximize your fitness without shelling out for expensive appointments? Are you dealing with regular muscle pain or discomfort that interferes with your active life-style? Often feel tired when working and traveling? This Pulse Muscle Stimulator for Pain Relief is just what you need5. Easy to Use: One key to start, put your finger on the power switch button in the middle, press and hold for 3 seconds to start the machine, then you can press + to increase the pulse intensity. You can also briefly press the power switch button in the middle to switch modes while the machine is running.SpecificationMaterial: PU, PETColor: BlackSize: 17.5 X 6.8 cmWeight: 100 gPackage Include:1x Muscle Massager 1x Charging Cableor2x Muscle Massager 1x Charging Cableor3x Muscle Massager 1x Charging Cable