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A highest-quality Hop-Up chamber intended for tuning you replicas! CNC Aluminum Hopup Chamber M4W Pro (with new BB Latching System) unit is precisely made to improve accuracy and ensure consistent air seal for your HPA MTW Milspec, Forged, Billet and MTW-9 series.


  • Machined from a solid aircraft aluminum block with tight tolerances to achieve the most accuracy, consistency, and durability
  • Precision Rotary Dial Knob for fine hopup adjustments
  • Re-engineered the precision Hopup Lever and 4mm Bucking Nubs (6mm Bucking Nubs are optional) to perform best with R-Hop and Standard-Hop to keep the BB shooting accurately and consistently on every single shot
  • Removable Steel Pivot Pin for ease of setup and maintenance
  • Accepted the HPA MTW Engine M4 nozzle length
  • Fully compatible with most aftermarket soft and hard rubber buckings without losing FPS or dropping BB during use
  • Wisely equipped with an interchangeable Inlet Adaptor OD11mm to ensure the hopup unit is inserted exactly in the center of the 11mm inner bore HPA Engine nozzle outlet without wobbling. (Inlet Adaptor OD11.5mm and OD12mm are sold separately)
  • Mounted the removable CNC Brass Side Wings to slide smoothly into the outer barrel slots
  • Included an advanced CNC Delrin Locking C-Clip to hold the inner barrel tight in place without wobbling and twisting
  • Equipped with 2 compression springs on top and center to ensure the hopup unit is seated straight and air tight during use
  • Compatible with any 11mm inner bore HPA Engine nozzle outlets
  • The Dual UV LED Tracer Module to glow BB in the dark ready!
  • Compatible Gun: HPA MTW Milspec, Forged, Billet and MTW-9 series
  • Inlet Adaptor Outer Diameter (to fit into HPA Nozzle Outlet): 11mm
  • Hub Outer Diameter (to fit into Outer Barrel): 12mm
  • Hub Inner Diameter (to fit Nozzle): 8mm
  • Overall Length: 51.15mm
  • Overall Height: 22 mm
  • Material: Aluminum 6061


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