GrovTec US M-LOK 1.3in 3-Slot Rail Black. Precision CNC machined from lightweight solid aluminum with Type III Black Anodized Finish. MIL-STD 1913 Picatinny rail pattern allows mounting a variety of lasers sights scopes or other accessories. Specifications for GrovTec US M-LOK 1.3in 3-Slot Rail: Manufacturer: GrovTec US Color: Black Finish: Anodized Fabric/Material: Solid Aluminum Gun Rail: MIL-STD 1913 Picatinny Width: 1.3 in Package Contents: GrovTec US M-LOK 1.3in 3-Slot Rail Key for installation GrovTec US GTSW226: M-LOK 1.3in 3-Slot Rail Black