The Sea to Summit 1-Pin Side-Release Field Repair Buckle replaces a single-side adjustable buckle like the type found on top-loading backpacks.
Features
Stainless-steel pin holds the buckle together permanently; a Phillips head screwdriver securely attaches the buckle to the webbing on your pack's strap
Since the buckle is permanent, there's no need to have your new buckle sewn on when you're back home