The Centurion patented C4 rail system is a lightweight, rugged, 2 piece free float rail that when installed gives the uppers a continuous 12o'clock rail. The C4 system is the lightest and most rigid rail that clamps to a standard barrel nut on all AR15, M4, and M16 type weapons systems. This design allows the installation of the rail on an upper assembly without removing the front sight post or permanently attached muzzle devices.
Material: 6061 T6
Finish: : type 3 hard coat anodized
Weight: 12.4oz with screws---1.1oz with standard barrel nut
Length: Top 9 1/4in Sides 11 1/2in Bottom 10 5/8in
Inside diameter: 1.37
Rails: 1913 spec rail
Fasteners: grade 8 bolts phosphate finished
MADE IN USA
This rail is the best quad rail I have ever used. Lightweight, locks up tight, precisely machined. It feels indestructible. This rail brought me back to quad rails from the Keymod/MLOK dark side. My favorite rail by far, saving up for another.
Got this secondhand and am in process of saving for a comolete 12,5 with fsp and this rail. It is on my short list of factory rifles.
Now, on to the rail. Its incredible. I honestly dont know how dd got their risII accepted instead of this... Its lighter, better, more appealing anf appears stronger!
Bottom line? Get it.