Oh, yeah, I forgot to mention. I don't know if you have the same problem with yours, but my FIRSH seems to have the rails 2-3mm to close to the tube, thus causing (2) problems. 1.) the foregrips won't slide easily onto the rails because of the top inside edges hitting the tube when its being slid on. I had to file down the two inside top corners of my AAC to "miss" the tube itself. 2.) Because the rails is slightly lower, the upper rails the rails on the tube don't match up on the top like the Oly pic shows. LOL, these were problems I encountered, but it dosen't really matter to me, since it dosen't interfere much with how I use it. Good thing about the AAC is that its polymer, thus easy to file down. Unfortunately, the AAC dosen't have the compartment to hold batteries.
Ghost