I use this and a harris bipod on a 20'' flat-top SNS VMT and love it! I ordered a couple more, just to have on hand.

I installed this on my older Bushmaster H BAR AR 15 with a round hand gaurd. It took maybe five minutes, fit perfectly and now my Harris bipod goes on the AR as easily as on the bolt guns. This was the inexpensive solution I had been looking for.

I ordered this item and after alittle adjustment it worked perfectly. I have a bushmaster M4 A3, in order for it to fit i had to remove the stainless steel heatshield then cut off the two tabs on either end of this adapter, reinstall the shield, and the gaurd went right back into place, but it only will fit in the middle of hand gaurd on the carbine length so if all you want is a bipod then it is perfect and i recomend this item. but if you want a hand grip aswell it will not fit comfortably so use this on your factory grip and then get a quad rail fortactical accessories, being that the handgaurd changes so easily that you can have both at not to much of a cost.