This piston is for folks who want to run their ERECT9R on a  M13.5 x 1 LH threaded barrel.

Specs: 

• MATERIAL: 17-4 Stainless Steel 
• COATING: Head Treated
• WEIGHT: 1.12 Oz
• THREAD PATTERN: M13.5 x 1 LH

If you have a fixed barrel firearm DO NOT run your ERECT9R with the piston. Direct mounts can be purchased here.