Most cars have the Recycle switch as a turnable/slidable knob which pulls (say) a flap over to go from Fresh to Recycle cabin air.

In my GL Mk3 its electrical, does anyone know what that elecrical button does (e.g. turns on a solenoid that pulls a lever/flap over, etc etc)
97 1997 Volkswagen Golf A/C Switch - Climate Control - OEQ - PartsGeek