feature: Rails are designed for use with standard Keymod rail systems Rails quickly mount to any common Keymod platform, allowing quick modular attachment of grips, bipods, sights or other accessories. The rails are made of lightweight aerospace grade aluminum. hollow carved design. Glasses: Length: 9.5cm/7.5cm/2cm Color: Matte Black Size: 3 slot hollow bead: length 55mm, hole spacing 40mm 5 slot hollow bead: length 75mm, hole spacing 60mm 7-slot hollow bead: length 95mm, hole spacing 80mm Package includes: 1*3-slot guide rail 1 x 5-slot guide rail 1 x 7-slot guide rail 3*Allen wrench 6*Keymod screws and nuts Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin