Colt six position carbine buffer tube. Used on SOPMOD MK18, Block 2 M4A1, and Block 2 MK18 rebuilds. Not the standard 4 position used on regular production Colt carbines. 7075-T6 aluminum tube with gray dry lube on the inside. Factory black anodizing. OEM military 1.15″ diameter. Impossible to find.
The buffer tube you will receive will come in the sealed Mil-STD Colt poly bag as shown.