The Multi-Key is a multi-function external device designed for the safe interface of modern transceivers and RF amplifiers. For those that prefer an external interface to those that mount inside the amplifier, this kit fits the bill! You can now interface any amateur transceiver with any amplifier safely and quickly. The Multi-Key features 2 solid state relays capable of switching loads of 200 peak volts DC or AC at 250mA of current. It also has 2 accessory jacks for control of other devices, such as an ON-AIR sign or a Dow-Key relay. The possible uses for the accessory connections are endless! The main PLA140 outputs can safely switch up to 400V and the accessory ground-isolated outputs can safely switch up to 220VDC or 250VAC at 3A of current. NOTE: Due to the length of the instruction manual for this kit, printed instructions are not sent with the kit. I will email a PDF version of the manual, with detailed step-by-step assembly/installation, testing and user instructions.