Armory Craft P220/4/5A1/6/7/8/9/M11A1 DA/SA Skeletonized HammerWill fit these DA SA models: P220 P224 P225A1 (2015 and newer) P226 P227 P228 P229 M11A1 The purpose of a reduced weight hammer, (just like a reduced weight firing pin), is to reduce the lock time, which makes it easier to get a reliable low weight trigger pull. Reduced mass hammer will produce *higher velocity* which gives a better energy transfer from the mainspring to the firing pin. (i. e., you can technically use a lighter mainspring which gives