Lately I have been sewing some pieces of gear such as weight pockets, dumpable weight systems side pockets etc and amongst that tank straps, buckle box stitch, a bit of velcro here and there you go, nothing special. But a few days ago two of my diving colleagues came with an idea to make a new strap for their Apeks black ice which came with this convoluted contraption they call the griplock system. What are these intended for? Are they for aluminum tanks or some other standard because they barely fit a 15L steel tank and they both want the capability to go up to 18L steel. I don't understand why they are adjustable on both sides and they use an uncommon 45mm strap. Has anyone heard of these slipping or failing, the buckle seems fine but everything else seems sketchy considering this is a fairly expensive bcd?