1Electrode lead wire, fit for most portable electrotherapy units. 2Tens/EMS Machines electrode lead wires with 2.5mm plug. 3The lead wire is used to connect the current from the TENS device to your electrodes. 4It needs to be used with a therapy machine and patch. 5There are 2 pins and 4 pins available, you can choose according to your needs. Features: Electrode lead wire, fit for most portable electrotherapy units. Tens/EMS Machines electrode lead wires with 2.5mm plug. The lead wire is used to connect the current from the TENS device to your electrodes. It needs to be used with a therapy machine and patch. There are 2 pins and 4 pins available, you can choose according to your needs. Specification: Condition: 100% Brand New Plug: 2.5mm Optional Type: 2 Pins, 4 Pins Package List: 10 x Electrode Lead Wire