Jk Armament Piston Features The Jk Armament Piston is precision machined from 17-4 PH stainless steel a material chosen for its strength and resistance to the repeated cycling stress a booster piston experiences on a semi-automatic pistol. Designed for 9mm pistols using a 1/2x28 thread pattern this piston screws directly onto the threaded barrel creating the mechanical link that allows the slide to cycle normally once a suppressor is mounted. Without a properly fitted piston many suppressed pistols fail to cycle reliably so this component is essential to maintaining semi-automatic function. Its 1.55 diameter is sized to mate cleanly with compatible suppressor hosts keeping the barrel and suppressor properly aligned through every cycle of fire. The black Nitride finish adds a layer of corrosion resistance and surface hardness helping the piston withstand the heat and friction generated during suppressed fire. Jk Armament offers this piston in both 1/2x28 and .578x28 thread patterns covering the vast majority of 9mm and .45 ACP pistols on the market so shooters running either common pistol caliber can find a matching piston for their host gun. Because the piston is a dedicated wear component that absorbs the brunt of suppressed cycling forces a durable finish and quality steel matter for long-term reliability rather than a one-off fix. This Jk Armament Piston gives suppressor owners a dependable way to keep their pistol cycling properly shot after shot available for sale at GrabAGun for anyone building out a reliable suppressed 9mm setup. JK Armament Piston Specifications Manufacturer: JK Armament Model: Piston Caliber: 9mm Color: Black Material: Stainless Steel Finish: Nitride Diameter: 1.55 Thread Pattern: 1/2x28 Available At: GrabAGun