iStim EV-804: Rechargeable TENS EMS combo stimulator comes with 2 channels, 5 TENS + 2 EMS modes and 24 preset programs, sending comfortable impulses through the skin that stimulate the nerve fibers in the treatment area (e.g. shoulder tension, back pain, arthritic, knee pain) and provides muscle relaxation and muscle strengthening. JAPANESE ELECTRODE PADS: High-grade, and biocompatible 100% SEKISUI Japanese gel, which facilitates efficient conducting of the electrical stimulator's current to the patient's skin in a dispersed manner. APPROVAL: Approved for the safe, all-natural, drug free and long-lasting pain relief. 510K approved for OTC use. Made in Taiwan. PRODUCT SET: iStim EV-804 Unit x 1; Electrode Pads x 8; Lead Wires x 2 ; Instruction Manual x 1; Quick Guide x 2; USB Charger & Lead x 1; Carrying Case x 1 NOTE: DO NOT USE Extra Electrode Gel