Designed from the ground up for use on AR style rifles. The Primary Arms 5X Prism Scope with our Patented ACSS Reticle, "Advanced Combined Sighting System" combining Bullet Drop Compensation, Range Estimation, Wind and Leads in one easy to use system. Waterproof, fog resistant and also fits on ACOG mounts! Base can be removed for use on AR15/M16 carry handles. Front and rear flip up caps are included!