The Twin Stim Which Gives The User The Choice Of Five Modes Of Tens And Two Modes Of Ems Features Include Dual Channels Seven Modes Timer Patient Compliance Meter New Stronger 100 Ma Output Safety Amplitude Cover Sturdy Metal Belt Clip And Rubber Side Railings For Maximum Handling Five Tens Modes: Burst / Normal / Modulation / Sd1 / Sd2 Two Ems Modes: Synchronous Alternate System Includes Device Lead Wires Four Self-adhesive Reusable Electrodes 9-volt Battery Hard Plastic Carrying Case And Instruction Manual Patient Compliance Meter Can Store Up To 60 Sets Of Operation Manual Power Source: 9-volt Battery Pulse Width: 50-300 S Adjustable Pulse Rate: 2-150 Hz Adjustable Pulse Ramp: 1-8 Seconds Pulse Amplitude: 100 Ma Peak Into 500 Phm Load Contraction Time: 2-90 Seconds Relaxation Time: 2-90 Seconds Wave Form: Asymmetrical Bi-phase Square Pulse Timer: 1-60 Minutes Or Continuous One Year Warranty