Airsoft Outlet Northwest now have in stock the rail systems from Centurion Arms which are licensed to PTS Syndicate... "PTS just released their new licensed Centurion Arms rail systems, and these are extremely impressive. Two styles are available, including the C4, which is a free float quad rail, and the CMR, which is a modular rail handguard.

The Centurion C4 comes in two lengths, the 7 inch Carbine and the 9 inch Midlength. Both of these are designed to lock onto a GI barrel nut with the delta ring assembly removed. This allows the rail to upgrade any M4 or AR15, without needing a proprietary mount."

Read more about the PTS Centurion Arms Rails at AONW.