The Optimus retains the ability to use the Low Profile 3 Lug System for fixed barrel firearms. The existing A2 adapter also still functions with new Gen 2 Optimus ensuring AR15 firearms can be fitted with a logical mounting option. Additionally, included is a Taper Mount Adapter and EZ-Brake (no timing required), which provides an accurate out of the box system that Griffin end users typically apply to rifles of all categories. The taper mount system is a mainstay of the Griffin product line and has been proven over a decade of use. Various mounts are available offering different performance benefits depending on end user desires.