Backpack Buckle V2

As much as I love 3D printing, I still don't fully trust it to support my 30 lbs. backpack. So for all of those out there like me who whose backpacks undergo more trauma than a HALO parachutist, here's an indestructible buckle.
New and improved adjustable backpack buckle. Works with flat straps up to 26 mm wide.
It uses 5 mm thick Delrin, but other materials can be used.