The HWS 552 series has seen extensive use worldwide as the close-quarters optic of choice by numerous military, police, and special forces units. EOTECH's HWS (Holographic Weapon Sight) utilizes holographic technology to greatly reduce parallax when acquiring an off-center sight picture, allowing for a point of impact closer to the sighted in point of aim. The standard full-size option allows the sight to accommodate two AA batteries, allowing for a longer operational life. The optic also includes infrared brightness settings for use with night vision optics and comes with an 8-hour auto shutoff feature to help conserve battery life. The XR308 variant features a reticle that is designed to be used with the military M240 machine gun and its semiautomatic commercial counterparts. This model features an all black finish and includes two AA batteries. The manufacturer recommends usage of the sight with 150-grain .308 Winchester ammunition (M59 FMJ; 2800 fps) out of a 24.8-inch barrel for optimal ranging with the reticle.