This Magazine is for the RUGER Mark II .22 Long Rifle, Semi-Auto Pistol, 10 round capacity and is manufactured by TRIPLE K. It has a Lifetime Warranty through TRIPLE K Manufacturing. The Spring retractor magazine is reversible. The Spring Retract Button on the Magazine is on the opposite Side, do the following: Push the Follower all the way down, Pull the Retract Button out and Reverse Sides, Then release the follower and the magazine will function properly. It can be on either side, depending on which model of Ruger Auto 22 you have. Specific state laws prohibit the sale and shipment of this magazine; we CANNOT sell or ship to California, Maryland, Hawaii, Massachusetts, New York, and New Jersey.