The Warne A645 machined aluminum Side Mount is designed for Flat Top MSR?s and other tactical style firearms. It provides a 45 degree accessory platform that attaches to a Picatinny style rail. The A645 Mount can also be mounted to the rail on the hand guard to allow your back-up sight to co-witness with the sight on your R.A.M.P. Mount.To add to its already sleek design, the A645 Side Mount has been redesigned to incorporate two cut out sections to achieve an ultra-lightweight feel. The side rails have also been updated with one more additional cross slot to increase the mounting capabilities to 4 slots total.This is a simple installation and requires no modification to your firearm.