The switch that comes with the Koonlung K1S is just a basic push button with an indicator LED, connected to a micro USB male connector which goes into the side of the unit. It's purpose is to allow easy access to start/stop recording functions, as well as emergency file locking. I couldn't find an ideal place to mount the button in my P11 Nissan Primera, so I grabbed a spare rear window demister switch and a friend of mine rewired it to the original USB cable. The button is installed where a switch blank would normally be.