Features: Multi-slot rails are available in 3, 5, 9, and 11 optional slots. The Picatinny rail accessory is designed to be attached to M-LOK handguards. These multi-slot rails for M-LOK are lightweight, strong, and durable due to their high-quality aluminum alloy construction with precision black treatment. Each rail comes with 2 screws, 2 T-nuts, and a hex key. Specification: Material: aluminum alloy. Color: black. Rail width: approximately 2cm. Rail length: 3 slots: 4cm, 5 slots: 6cm, 9 slots: 10cm, 11 slots: 12cm. Weight: approximately 22 ~ 51g. Package list: 1 rail section, 1 set of accessories.