The K22 X-Trim Mk23 is the little brother of the X-Calibur in 9mm. Like others in the Mk23 lineup, the K22 has been upgraded and updated. You'll quickly notice the new slide design with more aggressive serrations to allow an easier and more secure purchase on the slide for manipulation. It not only comes standard with fiber optic front and rear sights, it also is optics ready straight out of the box. The K22 still comes standard with interchangeable back straps, and it's two-spring system to tune for any ammo you choose. If you're looking for one of the most pleasurable to shoot .22 pistols on the market, look no further.