I just got a New Knights M5 RAS for 20" barreled rifle. I have installed the RAS for M4 carbines before, so no problem there. I did not get the small photocopied instruction sheet with it, but it was new sealed in the box.
It came with a small "U" shaped piece of metal, about an inch and a half long, that has two small springs on it. Where does this go? Thanks, Geoff