Angstadt Arms AAUMDP0906 MDP-9 Roller Delayed 9mm 5.85" Black Type III Hard Coat Anodized Barrel The MDP-9 Is Designed To Be Light, Small, Yet Fully Functional, Offering a Revolutionary Roller Delay Action That reduces Recoil. Gain The Peace Of Mind And Confidence Needed For Protection In Any Situation, With The Perfect Balance Of Size And Strength. Caliber: 9mm Barrel Length: 5.85" Barrel Material: 7075-T6 Aluminum Twist: 1:10" Barrel Finish: Black Type III Hard Coat Anodized