Easy Drop-In install, no special gunsmithing involved, fit into Delta Ring and front Handguard Cap. Remove factory handguard, drop in the KeyMod handguards and use supplied four screws to secure KeyMod handguard in place. Includes: - Two Accessory KeyMod to Picatinny Rail Sections. - One Short (5 Slot Picatinny) - One Medium (11 Slot Picatinny) Length Picatinny Rail sections. They can be placed in any of the sides or bottom KeyMod slots Features: - Solid fit, top rail is at receiver height and you have KeyMod slots along each sides and the bottom of the handguard.