Genuine FX OEM Part 20858, replaces the Delrin (plastic) 19696 16mm regulator piston

Made of brass with a small Delrin seal on top. Comes with 4x1.5 NBR70 O-ring installed

Fits any FX rifle taking a 16mm regulator piston 

Examples: 

• FX Impact Mk2 & M3
• FX Crown Mk1 & Mk2
• FX Wildcat Mk3 & BT (brass AMP regulator models) 
• FX Wildcat Mk2 (AMP regulated models [external adj.])
• FX Dreamline
• FX Maverick
  
• FX Panthera
• FX Dynamic
• FX King
• FX DRS / DRS Pro

All rifles after approximately mid-2023 should have this piston installed from factory.