I have mounted this fore grip on my Remington 870 and have been quite pleased with the results. It is sturdy and I have used the rails to mount a TLR 1 and a vertical grip. The product is lightweight and the option to remove the left and right rail if they are not being used is a great asset. The installation is not overly complicated, but if you are unfamiliar with disassembling your firearm fully it may present a bit of a challenge. (I recommend the use of youtube videos if you need a walkthrough on disassembly.) My only notable complaint is that there is slight side to side play on the grip. However, it is not enough to bother me too much.
I have been using this mod for over six months now and I would recommend it to a friend.
Pros: Durable, Adds Utility, Flexibility, Grip.
Cons: Not Cheap.
This review was written in the old system and had content requirements that are different than reviews written today.