Volquartsen Firearms Extended Magazine Release for MK IV Black Nitride. This improves feeding by preventing the bolt from sliding over the round in the magazine. It's also knurled for both aesthetics and feel. Our release will work with the factory magazines however due to magazine being raised it is highly recommended the Magazine Release is used in conjunction with our Specifications for Volquartsen Firearms Extended Magazine Release for MK IV: Manufacturer: Volquartsen Firearms Gun Make: Ruger Gun Model: Ruger 22/45 Color: Black Finish: Nitride Fabric/Material: Aluminum Condition: New Country of Origin: USA Features of Volquartsen Firearms Extended Magazine Release for MK IV Black nitride finish Only compatible with 22/45-style pistols Package Contents: Volquartsen Firearms Extended Magazine Release for MK IV Black nitride finish Only compatible with 22/45-style pistols What firearm models does the manufacturer say Volquartsen Firearms Extended Magazine Release for MK IV is compatible with? The manufacturer suggests that Volquartsen Firearms Extended Magazine Release for MK IV is compatible with Ruger 22/45Volquartsen Firearms VC4MR: Extended Magazine Release for MK IV Black Nitride