Dual Channel, 3 Modes, Timer, Safety Amplitude Cap. The TENS 3000 is a high quality TENS unit that uses the newest technology of a microprocessor, which gives exact dial performance. The TENS 3000 has the ease of operation of an analog unit with the accuracy of a digital unit! The TENS 3000 comes standard with a Safety Amplitude Cap, which is a transparent pivoting cap that closes over the amplitude knobs to help protect the user from power jolts from accidental knob movements.