User-driven units feature a wide array of output combinations to help ensure proper settings. Features three modes B Burst , N Normal and M Modulation . The pulse rate, pulse width and amplitude are adjustable to lessen acute pains due to an accident or chronic conditions, such as arthritis or other joint and muscle conditions. Sturdy construction with an attractive appearance. Protective cover to guard against accidental setting changes. Zero Start feature for shock prevention- if the output is not set to while the battery is being connected, unit will not operate. Amplitude is adjustable, 0- 80mA peak into 500-ohm load each channel. Waveform is asymmetrical biphasic pulse. Analog. Pulse rate is adjustable, 2 Hz 150 Hz. Pulse width is adjustable, 30 s 260 s. Timer range from 15 or 30 minutes to continuous mode. Features Fully adjustable. Convenience Sturdy construction with an attractive appearance. Protective cover to guard against accidental setting changes. Zero Start Feature Shock Prevention . Specifications Channel Dual Amplitude Adjustable, 0-80mA peak into 500 ohm load each channel Pulse Rate Adjustable, 2 150 Hz Pulse Width Adjustable, 30 260 us Mode B Burst mode N Normal constant mode M Modulation mode Wave Form Asymmetrical biphasic pulse Timer 15, 30, continue Power Supply 9V Battery Size 105 H x 70 W x 24 T mm Weight 127g battery included Includes TENS Unit Four 4 TENS Electrode Two 2 Leadwires 9V Battery, type 6F22 Instruction Manual Carrying Case 1 Each / Each