American Built Arms Company Polymer Picatinny Rail M-LOK 4 Slot Black. Specifications for American Built Arms Company M-LOK 4 Slot Polymer Picatinny Rail: Manufacturer: American Built Arms Company Color: Black Fabric/Material: Fiber-Reinforced Polymer Gun Rail: Picatinny Hand: Ambidextrous Gun Type: Rifle Length: 6 in Width: 3 in Height: 0.65 in Weight: 0.25 oz Quantity: 1 Features of American Built Arms Company M-LOK 4 Slot Polymer Picatinny Rail Light weight polymer material reinforced with high strength fibers Continuous Mil Spec Picatinny rail designed to deliver maximum reliability This product is the single four (4) slot Picatinny Rail that comes with the M-LOK mounting hardware This M-LOK Picatinny rail is not compatible with the AB Arms MOD 1 or AB Pro carbine polymer hand guards Package Contents: American Built Arms Company M-LOK 4 Slot Polymer Picatinny Rail American Built Arms Company ABAMR4: Polymer Picatinny Rail M-LOK 4 Slot Black