9-12V Locking Solenoid
This solenoid in particular is nice and strong, which has a slug with a slanted cut and a good mounting bracket. It's basically an electronic lock, designed for a cabinet, safe, and door. Normally the lock is active so you can't open the door because the solenoid slug is in the way. It does not use any power in this state. When 9-12VDC is applied, the slug pulls in so it doesn't stick out anymore and the door can be opened.