GrovTec M1913 Picatinny M-Lok 15 Slot Rail - GrovTec's Picatinny M-Lok Rail is precision CNC machined from lightweight, solid aluminum with Type III Black Hard Anodized finish. The MIL-STD 1913 Picatinny rail pattern allows mounting a variety of lasers, sights and scopes or other accessories. It easily accommodates different-length attachments and provides for a wide adjustment of eye relief. 15 Slot 6in