Have a sluggish MKII, MKIII, MK IV, or 22/45 Ruger magazine? Chances are the spring is fine but the actual culprit is the metal on metal contact of the magazine button. Not only does this make magazines hard to load but it can also cause feeding problems by allowing the round to hang up before the bolt closes. If your magazine has a gritty and rough feeling when loading, we suggest using the Magazine Follower Button for incredibly smooth operation. The button is knurled for easy gripping but more importantly, it eliminates the metal on metal contact providing easy loading and trouble free feeding. FeaturesCase hardenedCNC-machined