Dead Air Odessa Piston 9mm Piston 1/2-28Dead Air Odessa Piston 9mm Piston 1 2 28 Designed for use with the Odessa 9 silencer; Compatible with all tilting barrel handguns; Available in 9mm barrel threads: 1 2 28 and Metric 13. 5x1LH; Ensures secure and reliable performance Item Category Code: 7600 Product Group Code: 7600P Inactive: No Prop65 Applies: Yes Prop65 Cancer Harm: Yes Prop65 Chemical: Lead