Battle Arms Development RIGIDRAIL™ M-LOK AR15/M16 Rail
Features:

Proprietary RIGIDRAIL™ rail design to balance between light weight and strength/rigidity
Partial Picatinny Top Rail (Matching BAD556-LW Lightweight Upper Receiver)
Material: Aircraft Grade 6061-T6 Aluminum
Length Options: 6.7in, 9.5in, 13.7in, 15in, 17in
Weights:6.7in, 5.9oz, 9.5in 7.3oz, 13.7in 9.0oz, 15in 9.6oz, 17in 10.44oz
Inner Diameter: Side to Side - 1.315in, Top to Bottom - 1.695in
M-LOK Slots at 3, 6, 9, and partial 12 o'clock positions
Additional Single M-LOK Slots at (4) 45° Positions for Forward Mounting Light, Laser, etc.
Barrel Nut Diameter: 1.378in
Barrel Nut: 7075 Aluminum Type 3 Class 2 Hard Anodized Clear (Bronze finish)
Barrel Nut Wrench Included
No Barrel Nut Shims Required for Installation
17-4PH Cored Stainless Steel Rail Mounting Attachment - Patent Pending by CMT
(4) Anti Rotation QD Sling Sockets: (2) at the front and (2) at the rear. 3 & 9 o'clock Positions
No Contact with Gas Tube
Compatible with most Low Profile Gas Blocks
Rotation limited QD sockets
Finish: Mil-Spec Type 3 Class 2 Hard-coat Anodized
Compatible with AR-15 Upper Receivers
Made in the USA