Yankee Hill Machine Nielsen Piston M13.5x1LH 9mm – Silver Finish

The YHM Nielsen Piston converts fixed-mount suppressors into tilting-barrel compatible systems for 9mm pistols with M13.5x1LH threading. This spring-loaded booster assembly allows the barrel to unlock and cycle properly when suppressed, preventing short-stroking and function failures common with direct-thread cans on Browning-style actions.

Precision-machined from heat-treated steel with a corrosion-resistant silver finish. Installs between your suppressor mount and the pistol's threaded barrel. Compatible with YHM 9mm suppressors and other manufacturers using Nielsen-device specifications. Essential for reliable suppressed operation on tilting-barrel pistols including many Glock, Beretta, and SIG Sauer models. This is a legally transferable suppressor accessory; the suppressor itself requires ATF Form 4 approval.

• Type: Nielsen Device / Booster Piston
• Caliber: 9mm
• Thread Pitch: M13.5x1LH (Left-Hand)
• Material: Heat-Treated Steel
• Finish: Silver
• Compatible Firearms: Tilting-barrel 9mm pistols with M13.5x1LH barrel threads