Memory Function TENS machine remembers and sets the massage mode you have applied last time without selecting your preferred modes again and again when power on. Whats more, long press the home button to activate the screen lock function, it helps to prevent any accidental touch during the use, thus it enables a muscle relaxing time for your own.Adjustable 20 Intensity Levels & Timer rechargeable TENS unit - equipped with 20 adjustable intensity levels - allows you to customize the frequency of the electrical impulses to fit your needs. Timer function lets you set an operating time limit (10-60 min), the default setting is 20 minutes. The timer indicator would keep you aware of the remaining time. With a built-in powerful rechargeable lithium battery, never worry about the suddenly power off!What you will receive 1 x TENS & EMS Machine, 4 Palm Electrode Pads, 2 Large Rectangle Pads, 2 Small Pads, 2 x 1/2 Lead Wires, 1 x 1/4 Lead Wires, 1 x USB cable, ,1 x User Manual, 1 x Pad Holder, 1 x Pouch, 12-Month Warranty , and our Friendly Customer Service.8 Reusable Electrode Pads, 2 Outputs The strong self-adhesive property was added in the reusable electrode pads thus enables much better performance and easy clean up to 40 times uses for a long lifespan. The electronic TENS massager dual output design allows to use it for 2 different body areas, or by 2 people simultaneously. It is perfect TENS for back and sciatica pain, shoulder tension and muscle relief.Note only the port connected well and at least 2 pads pasted on your body, could you adjust the intensity. Or you could not feel the modes and intensity.