Weaver Tactical AR-15/M16 Flat Top Riser Rail Made of the highest quality materials Hunting scopes mounts Another quality Bushnell product For AR-15/M16 flat top rifles Aircraft Grade 6061-T6 Aluminum Type III hard coat anodized Provides optimal mounting height and eye relief for numerous optic/ring combinations Hand adjustable knobs for no-tool installation and removal (Quick Detach model only)