Easy to install, but required a few mods - Command Arms Accessories Picattiny Rails

I installed these on an "Fat" carbine length handguard. While the 'pins' in the botton of the rails fit perfectly into stock guards, they did not want to line up with the holes in the bottom of the Fat guards. This was easily remedied by filing the holes in the guard a little to accommodate the rail's pins.

The rails also have a block at the end which needed to file off inorder to fit the angled grip I wanted to put on. This was easy enough since the rails are plastic.

These add on rails are not a perfect solution, but easy and affordable.