Works if you use the right rail - American Built Arms Company SBR-V Grip Vertical Grip

This item has a few reviews on this and other sites about the bolts not being long enough. This isn’t the case. The item was designed to fit standard or high profile Picitinny rail. If yours is a low profile pic rail, it won’t work out of the box. Since most Mlok and keymod add in rails are low profile, I imagine a lot of people run into this. The solution is to either get a high profile rail section or do a little fitting work and you’ll be rolling. For fitting to low profile you need to sand material off the top rails of the mount and it will fit low profile rail. I used a belt sander flipped over and held the grip mount against the belt then finished with a file and some fine grit sand paper. I’d have gotten a high profile rail, but I’m cheap and have tools. Just be careful not to sand off too much. Go slow and test fit several times until it goes on.