I had bought this adapter for my Opel Year 2001. Between ~ 1998 and ~ 2004, Opel has allowed a joke, and the standard (!) ISO connector for radios ignition Plus and duration-Plus to exchange. The radio can be connected indeed, but after removing the ignition key, the radio may lack voltage from the battery save any settings. (Since 2004, you need to connect an external radio a sinfully expensive CAN bus adapter, which makes up for 50 to 80EUR to book!) This adapter has a break with plug and socket in the wires for ignition and continuous plus-plus. If necessary, you can connect these two wires cross, and has thus again the standard ISO connection, you need that on his radio. Practical is not really.