Bravo Company 3 Aluminum Picatinny Rail Section, MLOK Compatible, Black BCM-MCMR-1913-A3 Bravo Company's BCM 3 Inch Aluminum Picatinny Rail Section" M-Lok Compatible" is made of hard anodized aircraft aluminum alloy. It is made to the Mil-Standard 1913 Picatinny Arsenal Specifications and it features a snag resistant design while retaining Mil-Standards.