FeaturesPicatinny accessory rail sections for M-LOK systems. Fits All Standard M-Lok System - Picatinny 20mm weaver rails.Ideal for attaching lights, laser, optics, bipods, and gripsFive different sizes: 2.5" with 5 slots, 3.3" with 7 slots, 4.0" with 9 slots, 4.9" with 11 slots, 5.7" with 13 slotsLightweight and sturdy, made of fiber reinforced engineering polymerMounting screws and tools included SpecificationsDimensions:Rail #1 5.7" (length) x 9mm (height) x 20mm (width)Rail #2 4.9" (length) x 9mm (height) x 20mm (width)Rail #3 4.0" (length) x 9mm (height) x 20mm (width)Rail #4 3.3" (length) x 9mm (height) x 20mm (width)Rail #5 2.5" (length) x 9mm (height) x 20mm (width)Material: PolymerColor: Black / Tan (choose your color) Items IncludedOne (1) 2.5" / 5 slot M-LOK Picatinny Rail SectionOne (1) 3.3" / 7 slot M-LOK Picatinny Rail SectionOne (1) 4.0" / 9 slot M-LOK Picatinny Rail SectionOne (1) 4.9" / 11 slot M-LOK Picatinny Rail SectionOne (1) 5.7" / 13 slot M-LOK Picatinny Rail SectionTen (10) sets of mounting screwsOne (1) Allen wrench