This Volquartsen Pistol Competition Kit includes the MK IV Accurizing Kit and Bolt Tune-Up Kit. The Pistol Competition Kit is designed to produce a crisp, clean 2.25 trigger pull, eliminate stovepipes, and eliminate failures to fire! Trying to figure out which parts are needed to take the Ruger MK IV or MK IV 22/45 to the next level? Look no further than the Pistol Competition Kit. FeaturesCrisp, clean 2.25 trigger pullFits all variations of the Ruger MK IV (including 22/45 and 22/45 Lite)Eliminate stovepipes and failures to fire