Please explain Key Mod in ref to rails.?

Key Mod is an alternative method of attaching accessories to an AR platform rifle. Most forearms utilize m1913 picatinny rails as a means of attaching accessories such as forward grips, lights, lasers, etc, to the rifles forearm. The downside of these rails is that they are not comfortable to hold, and if not protected, are exposed and susceptible to damage.

Key Mod is a system devised to eliminate this. Instead of having a series of rails on the forearm, there is a series of specially designed holes. Small rails and other accessory mounts which mate to these holes can be attached where needed, leaving the rest of the forearm clear.

Machining the picatinny rails is also labor intensive compared to the keymod holes.

Picatinny Rails: https://encrypted-tbn3.gstatic.com/images?q=tbn:AN...

Key Mod: https://encrypted-tbn3.gstatic.com/images?q=tbn:AN...

Key Mod be a key with a mod for sure dude. My granny be having one.