Interface is based on certified ISO9141 Bus Transceivers and RS232 level shifters
K-Line & L-Line (K/L Interface)
Bi-Colour status LED`s for K-Line & L-Line
Power LED
Powered from car battery over service cable
2x2 adapter for older cars. Volkswagen models often have it under the shift-boot or somewhere in the dash. Audis often have it in a fuse/relay box under the hood, or in the passenger's footwell under the carpets.