Features
Machined from a solid aircraft aluminum block with tight tolerances to provide better accuracy, consistency, and durability
Precision rotary dial design for fine hopup adjustments
Re-engineered the hopup levers and nubs to work best with R-hop, Flat-Hop and Standard-Hop to keep the BBs shooting straight and accurate on every single shot
Accepted the nozzle length from 21.00mm to 21.25mm
Fully compatible with most aftermarket soft and hard rubber bucking without losing FPS or dropping BBs
Equipped with a new CNC Delrin Locking C-Clip design to hold barrel tight without wobbling and twisting, 3 compression springs on top, at bottom and in center of housing to ensure the hopup unit is exactly centered, straight and air tight
Compatible with any 12mm inner bore ICS AEG Gearbox/HPA Engine nozzle outlets
Specially designed with BB Latching System to prevent dropping BBs after removing the magazine, manually opened to release BBs from inside hopup chamber by hand
CNC Aluminum Hopup Chamber M4A Pro (with BB Latching System) unit is precisely machined to perform accurately and consistently on ICS/CS4/EBB M4/M16 AEG series rifles.

The Hopup Chamber M4i unit is built with an aluminum rotary dial knob for fine hopup adjustments, the precision hopup lever and 4mm bucking nubs to perform best with R-Hop and standard-hop to keep the BB shooting accurately and consistently on every single shot.The Hopup Chamber M4i unit is designed to accept 21.00mm to 21.25mm nozzle length, and fully compatible with most aftermarket soft and hard rubber buckings without losing FPS or dropping BBs during use.

The Hopup Chamber M4i unit is wisely equipped with an interchangeable Inlet Adaptor OD12mm to ensure the hopup unit is inserted exactly in the center of the 12mm inner bore ICS AEG outlet without wobbling. Also mounted the removable CNC brass side wings to slide smoothly into the outer barrel slots, and included an advanced CNC Delrin locking C-clip to hold the inner barrel tightly in place without wobbling and twisting.

Additionally, the Hopup Chamber M4i Pro unit is specially designed with a new BB Latching System to prevent BBs from dropping after removing the magazine. The Latching Arm can also be manually pressed to release the remaining BB from inside the hopup chamber.
 
Manufacturer: Maxx Model
 
Specifications:
Hopup Kit Includes:
1 x CNC Aluminum Hopup Chamber M4i Pro (with BB Latching System) unit
2 x CNC Acrylic Side Cover
2 x CNC Brass 2.9mm Side Wing
1 x CNC Steel Pivot Pin
1 x CNC Aluminum Hopup Lever
1 x CNC Aluminum Soft Round Nub
1 x CNC Aluminum Soft Flat Nub (4mm)
1 x CNC Aluminum Hard Concave Nub (4mm)
3 x Steel Nub Spring
1 x CNC Steel Spring Guide
1 x Steel Upper Compression Spring
1 x Steel Center Compression Spring
1 x CNC Delrin Locking C-Clip
1 x CNC Brass Barrel Spacer
1 x Brass Barrel Spacer Holder Oring
1 x CNC Aluminum Rotary Dial Knob
1 x CNC Aluminum Inlet Adaptor (OD12mm)
1 x CNC Brass Inlet Spacer

Overall Length: 51.65mm
Overall Height: 37.75mm
Inlet Adaptor Outer Diameter (to fit into Gear Box): 12mm
Hub Outer Diameter (to fit into Outer Barrel): 12mm
Hub Inner Diameter (to fit Nozzle): 8mm
Feeder Outer Diameter (to fit magazine): 8.85mm
Feeder Length (to fit magazine): 6mm
Application: For most ICS CXP/CS4/EBB M4/M16 AEG series rifles
Material: Aluminum 6061

Test Results: FPS might be increased from 10FPS to 30FPS over the stock setup. Please check your FPS!
Disclaimer: Professional installation highly recommended. Please use discretion when installing custom parts as fit and compatibility may vary. Modification may be required. Professional installation recommended.