Made of nearly indestructible Zytel, these magazine bumpers are designed to enable your factory magazines to load one extra round. These have been designed to help with seating magazines securely into the pistol frame by providing extra material to "bump" them into a locked state. The Plus 1 Magazine Bumper also features a Spring Assist for even faster magazine ejection and assured magazine drop when the mag release is pressed. From competition shooters to casual backyard plinkers, everyone can benefit with these simple to install upgrades. Sold in packs of 2. Mfg: Tandemkross SPECS: These work on both the RugerA(R) Mark II(TM) and Mark III(TM) 22/45(TM) Magazines.