keyless

From key + -less.

keyless (not comparable)

1. Lacking or not requiring a key.
   • 2007 April 14, Micheline Maynard, “Car Keys Could Go the Way of Tail Fins”, in New York Times‎^[1]:

     Today’s keyless models use a fob — the small remote control device that most modern cars use to lock and unlock doors — but it performs the additional duty of sending a signal to the ignition.