"This magazine coupler works great. I used it for two GSG-5 magazines and they fit just fine. It holds much more securely than the $50 clamp sold specifically for the GSG-5. Those get lose after a while and don't hold worth a darn. The only concern with this one is not to over tighten, I would worry about stripping the screw. Over all a much superior product for a fifth of the price!"
"Got one for my MP5 Replica, for the price, I figure why not give it a shot. Works great. Just place it at the bottom of the mags and don't over tighten it."
"This does exactly what it's supposed to do. I have an Umarex H&K MP5 A-5 .22 LR and it clamps them together nicely. Cuts my first reload in less-than half the time before I have to start fumbling with my vest and pouches. I'm trying not to clamp it too tightly because the other reviewers said not to. This product is made very well, but if you don't clamp it tight enough, then you could probably just pull it apart with your hands. It will sustain the first reload in a firefight, but not a fall down a hill or something."