PROM-550 DIGITAL TENS UNIT TECHNICAL SPECIFICATIONS: Channels Dual, isolated between channels Dimension Width x Length x High: 6 x 10 x 2.5(cm) / 2.4 x 4 x 1(inch) Power Source 9 V DC battery Output Voltage Adjustable, from 0 to 30V( Max.output), 500ohm load Output Intensity Adjustable, from 0-60mA(Max. output) into 500phm load each channel.Each channel is adjustable by a control knob. Pulse Rate Adjustable, from 1 to 150 Hz Pulse Width Adjustable, from 30 to 300µ S Wave Form Asymmetrical bi-phasic rectangular pulse Treatment Modes Constant / Alternating / Synchronous Contraction Time On time, adjustable from 1 to 30 seconds Relaxation Time OFF time, adjustable from 1 to 30 seconds. Package Info Width x Length x High: 22 x 30 x 6.5(cm) / 8.8 x 12 x 2.61(inch) Weight: 685 G / 1.51 LB Main unit x 1, Battery x 1, Manual x 1, Electrode Pad x 4, Lead Wire x 2 There may be up to a +/- 20% tolerance of all specifications. Kit Includes: EMS ProM-550 stimulator, Lead wires (new FDA compliant), Pack of 4 self stick hypoallergenic reusable electrodes, One 9 volt battery, Hard plastic carrying case, Instruction booklet. HOW TO USE THE PROM-550 DIGITAL TENS UNIT? Check Battery Be sure you are using a fresh battery. Insert battery into battery compartment matching + and - indicators. Prepare Skin Before attaching electrodes, identify those placement areas where your physician has recommended. Each location should be cleaned, rinsed and thoroughly dried. Lead Wires The use of the conductive medium is subject to the specifications of the component parts contained in the unit or recommended by the dealer. Insert Pin into Electrode Socket Insert pin connector into electrode socket. It may be preferable to insert the pin connector before attaching the electrode to the skin. Adjusting the Controls Be sure both amplitude controls for Channel I and II B are turned to " OFF " position. Connect Lead Wire to Classic TENS Plug end of lead wire into the channel output receptacle to be use (A and / or B), pushing plug in as far as it will go. Place Electrodes on Skin The use of the conductive medium is subject to the specifications of the component parts contained in the unit or recommended by the dealer.