I just wanted to let you all know about phone conversation I just had with a very nice gentleman at Ergo Grips about their new accessory rail that mounts directly to the M4 handguards that you also may have seen in Shotgun News lately. The website http://www.ergogrips.net/ doesn't show it yet, so I called to ask about it. The one they currently have is one in the same as Calvary Arm's, but anyday they will have their own which differs by the lack of the channel that runs from front to back. This one will be more sturdy and look better in my opinion. Cost is $40 and $4 for shipping for either. Pay Pal accepted at their website. Item number is 4350 for the Calvary Arms made one and 4350N for the new beefier style. All hardware included. Just pop off inside heat shield and attach, and replace. I'm going to wait a couple days and get the new style. Just thought maybe some of you had some of the same questions that I did, and I was pleased so far by the service. Phone transfers to their home at night so not to miss any calls. I liked that.