Shield Sights RMSd Glass 1x Reflex Mini Sight D - 4MOA Dot - The RMSd is a compact, durable pistol red dot sight made from aerospace-grade aluminum for strength without added weight. Its low-profile design allows easy mounting and co-witnessing with standard sights on many Glock models-no suppressor sights needed. Automatic brightness adjustment provides a clear aiming point in any lighting, while a side-access battery drawer lets you swap batteries without removing the optic. Mounts to SHIELD's famous footprint.; Utilizes SHIELD's patented mechanism, enabling co-witnessing with standard iron sights, considerably reducing training times and costs.; The mechanism uses no click adjustment, making it infinitely more accurate when zeroing.; D-shaped, crystal-clear lens with no filters to disturb the image of the world through the sight.; Side-accessible battery drawer means there is no need to unmount the sight to change the battery.; Machined from aerospace-grade aluminium to extremely precise tolerances while maintaining an attractive, modern-looking optic.; Weighing only 18.5g (battery excluded).; Auto brightness adjustment, so it can always be on and ready.; 9000 hours in average daylight with a CR1632.;