RetroArms CNC Air Nozzle – 21mm Cylinder Heads Confirm compatibility with your gearbox

Confirm compatibility with your gearbox setup before purchase

Smooth gear meshing and consistent timing

and improve overall performance

the EPG promotes better wrist alignment and a more natural shooting position—ideal for both training and competitive gameplay

RetroArms CNC Air Nozzle – 21mm Cylinder Heads Confirm compatibility with your gearboxThe RetroArms CNC Air Nozzle 21mm is a high precision upgrade designed to improve air seal, feeding reliability, and overall consistency in your AEG build. Made from durable CNC machined aluminum, this nozzle features an internal O ring to maximize air pressure delivery between the cylinder head and hop up chamber. Perfect for custom setups or replacements, this 21mm nozzle is ideal for specific M4, MP5, or other platforms that require this exact