For use on MCR rifles and upper receiver assemblies, windage and elevation adjustable, mounts on MIL STD 1913 Pic Rail on MCR Feed and Top Cover Assemblies, Base machined from 6065 T6 aluminum billet, Base Hard Coat Anodized per MIL A 8625F, Type III, Class 2. Made in USA. Mfg: Fightlite Industries