CTS Mk 16 mod 1 CTS MK 16 mod 1 This upper is the 2nd Custom Upper offering from Carolina Tactical Supply. This package will be a pleaser for sure. Specs on the barrels: White Oak Armament turned Match Grade SS weight: 1lb 14oz Stainless Steel Mid Length Gas system Fluted under the guards M4 barrel extension (feed ramps) 223 wylde chamber 1/7 twist finish: bead blasted or regular stainless © 2006 Carolina Tactical Supply. All Rights Reserved.