Feature:   4-Channel TENS Device   Adopt TENS low-frequency pulse techniques to relieve pains. And with independent dual-channel output, it allows use by 4 person or in different areas and of different modes and intensity in channel A1, A2 and B1, B2.     Considerate Design  It offers 16 massage modes and 20 strength levels, free to choose to fulfil your different needs.     LCD Display  You can easily get to know the current massage mode, strength level and preset time of 4 channels.     Adjustable Timer  You can adjust time from 10 to 60 minutes by pressing "T" button, and it increases 10 minutes by each press.    Lock Function  It supports locking buttons to avoid any accidental clicks.    Long Lasting Battery  With built-in 200mAh battery, you can use it for a long time, and the remaining power of it is displayed on LCD screen.    Specification:  Material: ABS  Channel quantity: 4  Input voltage: AC 100~240V  Output voltage: 5V  Output current: 500mA  Power: 2.5W  Default time: 20min    Battery capacity: 200mAh  Display mode: LCD display  Mode: 16 modes  Strength levels: 0-20  Item size: 160* 54* 18mm/ 6.3* 2.13* 0.71in  Item weight: 84.8g/ 3oz (Only the host)    Packing list:  1 * TENS Device   8 * Electrode Pads (4 Medium, 4 Small)  4 * Electrode Cables ( 2-in-1 cables)  1 * USB Cable  1 * Pad Holder  1 * Power Adapter  1 * User Manual  1 * Acupoint Diagram