These are the "old standby" oval carabiners. With a breaking strength of 22kN (5000 lbs.), they are more than ideal as attachment hardware for leads, etc. They can also make your loop straps much more versatile by offering a way to connect your strap to objects that would otherwise damage your webbing. And, don't forget you need several carabiners to make a z-drag rescue set-up work properly.
