Cock cage

You reach into the box and pull out a small plastic device with a lockable latch on the side. It takes you a moment to realize what it is, then an even longer moment to accept the fact that you’re holding a cock cage in your hand. You search the box hoping to find something else but there’s nothing, not even a key to open it once it’s on.

You look over at the note again, that instructs you to put it on.