The Glock 41 Gen4 is a 45 Auto caliber pistol designed to maximize sight radius while achieving perfect weight distribution and balance. The longer barrel and slide help to reduce muzzle flip and felt recoil whereas the MOS Configuration makes it easy to mount a miniature reflex sight on the pistol's slide without the need for a new slide or separate mounting system. The modular back strap system makes it possible to instantly customize its grip to accommodate any hand size. The reversible magazine catch makes it ideal for left and right-handed shooters. Each Glock MOS model includes a cover plate and 4 adapter plates to fit the following optics:Trijicon RMRC-More STSEOTech Mini Red Dot, Docter Red Dot, Insight MRDS, Meopta MeoSightLeupold DeltaPoint Pro