This is the Directed 8613 ball bearing tilt switch.

A tilt switch triggers on movement rather than contact, which is how a security system knows the vehicle is being jacked up or lifted onto a tow truck. Inside is a roller ball bearing: tilt the vehicle far enough and the ball rolls onto the contact, completing the circuit and firing the trigger.

No mercury. Traditional tilt switches use a bead of mercury, and many jurisdictions now restrict it on environmental grounds. This one does the same job without it, which can matter for both compliance and disposal.

Run it through a relay rather than powering a circuit directly.

Prefer the traditional design? See the HE-7854 mercury tilt switch.