Panic snap

In horse tack, a panic snap is a mechanism often used between a lead and a horse's harness. They are useful because, unlike swivels or carabiners and similar fittings, they can be disconnected under load, as the panic snap is specially built so that the latching mechanism is separate from the load bearing structure.

They are sometimes dangerous, however, because leads or ropes under load can flail when freed. Panic snaps also find some use in suspension situations involving relatively light weights. Heavier masses are unsafe, with most panic snaps because of the possibility of injury from flailing cordage. They will usually require the services of a millwright.

Usage within consensual bondage
In BDSM and Bondage panic snaps are used to secure Bottoms in a safe way.