IF 4000 Analog Interferential Stimulator by Roscoe Medical.

Features:

The IF-4000 is an interferential stimulator that is small enough to be handheld but powerful enough to compare to professional devices. The current generated and sent through the skin by the IF-4000 interferes with the transmission of pain around the spinal cord. This is one of the most effective pain relief therapies being used right now. The IF-4000 current goes deep into the skin and delivers a greater pain relief therapy than other more common devices. Not only does it ease pain but also speed up the healing process. It comes with built-in safety amplitude cap.

4000Hz Fixed Difference of Carrier Frequency.
1-150Hz Adjustable Frequency.
Four Frequency Shifts: Continuous, 1/1 abrupt, 8/8 abrupt, 10/10 ramped.
Symmetrical Bi-Phasic Square.
Power Source: 9 Volt DC Adapter or 9V battery.
Includes device, carrying case, 1 pack of electrodes, lead wires, battery and manual.
11" x 3" x 9".

Singles.