The MFR Rail M-Lok QD Sling Mount, designed specifically for the Daniel Defense MFR Rail, allows for ambidextrous attachment of the popular push button sling swivel. This limited-rotation accessory mounts at designated points at the front and rear on both sides of the MRF Rail system for tangle-free attachment of slings. Steel Construction Heavy Manganese Phosphate Coated Weighs only .3 oz 1/8" Allen wrench included Made in the USA Not compatible with MFR XL Rail or any other M-LOK handguards. Mfg: Daniel Defense