This is what 2A Armament says:
The 2A Armament™ BL RAIL Gen 2 Keymod series was designed as a lightweight rail solution utilizing proven traditional 6061 extrusion, and titanium as the foundation. The BL RAIL Gen 2 series of rails features the same picatinny lightening cuts found on the BALIOS-lite Gen 2 and the Aethon receiver sets. When the two are combined, a seamless look is achieved across the top of the firearm. The BL RAIL is just as capable on any quality forged or billet upper receiver offered from other manufacturers as well. By utilizing a titanium barrel nut, and an innovative 45 degree mounting system, the BL RAIL achieves a solid lockup with the upper receiver. The 2A Armament Gen 2 BL RAILS will ship with a 6AL-4V titanium barrel nut. An optional aluminum barrel nut is offered as a separate item for those looking to save maximum weight on a build.
Note: If you have an earlier Balios Lite receiver set you will want to use the first generation BL RAIL series. See pictures for differences.
Made from U.S.A. sourced 6061 Extrusion
U.S.A. sourced 6AL-4V Titanium barrel nut as standard
Keymod mounting solution
Mil-Spec hardcoat black anodized
Free floating design
1.3” Internal Diameter
7” Rail with Titanium nut (weight 5.7 oz)(2A-BLRKM-7G2)
10” Rail with Titanium nut (weight 7.2 oz)(2A-BLRKM-10G2)
12” Rail with Titanium nut (weight 8.4 oz)(2A-BLRKM-12G2)
15” Rail with Titanium nut (weight 9.9 oz)(2A-BLRKM-15G2)
1-5/16” crows foot tool or premium armorers wrench recommended for installation (Not Included)
$179.00 Regular Price