110-220 to 12 volt DC (2 Amp). For when you use the Air Link with wall power, in a boathouse, sailing club, marina or at home during the off-season. Connect the above 12-volt DC power plug and wiring to this socket, and you’ll have a fuse and on/off switch (or the socket can be cut off this AC adapter if you don’t need the fuse and on/off switch).