Chain runs come apart at the connection point or not at all. The chain snap gives each end of a decorative chain a positive link to the post, so a closed-off display, an unused aisle, or a closed walkway stays visibly closed without loose ends dangling. Opening the barrier is just as simple: release the snap, walk the chain aside, and reconnect it when the area closes again. Keeping a few spares on hand lets you replace a lost or sprung link immediately and extend the working life of the chain itself.