Good product, could be improved - NC Star AAKLA AK-47/SKS Speed Loader for Detachable 7.62x39 Magazines

I can't comment on durability just yet, but I tested it when I got it on a few different mags. Here's the thing, I'm pretty sure it'll work 100% with any steel mag out there. With plastic mags it still works, but not as well. I think if you were to open up the post that goes over the back of the mag it might work better, but you can still get em in as is, it's just a little fiddly.