"I bought this for my Umarex G36C and DAMN was this a great addition. It doesn't shift or wobble on the rails, the bipod is extremely stable, and it clicks in and out crisply. I only have two complaints about it, and that's the weight and the button that deploys the bipod. This thing is unnecessarily heavy. It's not as heavy as an AEG or anything, but if you want to stay mobile I wouldn't recommend this. However, I'm not the strongest person I know, so it may just be me. But I can say that it makes my G36C feel almost twice as heavy when it's equipped, which is NOT fun when you're running around an outdoor field all day. Moving on to the button, it feels... awkward. With bare hands or fingerless gloves, I have no trouble pressing it on the fly. But with my shooting gloves, I need to push down with my thumb as hard as I can. This could be fixed by flipping the grip around and pressing the button with your trigger finger on your offhand (I'm a righty, so for me it's my left hand trigger finger). I can't do this, though, because of the sling attachment point on my G36C. I know I spent a lot of time on the two big negatives, but this thing is AWESOME. And for 13 bucks? Why haven't you clicked "add to cart" yet?"