MAXX CNC Aluminum Hopup Chamber M4i - PRO
SKU: 39855183500

MAXX CNC Aluminum Hopup Chamber M4i - PRO

Sale price$94.49 Regular price$104.99
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 7 - Jul 12

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

MAXX CNC Aluminum Hopup Chamber M4i - PROProduct Description CNC Aluminum Hopup Chamber M4i Pro (with BB Latching System) unit is precisely machined to perform accurately and consistently on ICS CXP CS4 EBB (include old models) M4 M16 AEG series. 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 (6mm Bucking Nubs are optional) to perform best with R Hop and Standard Hop to keep the BB shooting

Product Description

 

CNC Aluminum Hopup Chamber M4i Pro (with BB Latching System) unit is precisely machined to perform accurately and consistently on ICS CXP/CS4/EBB (include old models) M4/M16 AEG series.
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 (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.
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 BB 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 Gearbox nozzle outlet without wobbling. (Inlet Adaptor OD11mm and OD11.5mm are optional)
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 tight in place without wobbling and twisting.
More than that, the Hopup Chamber M4i Pro unit is specially designed with a new BB Latching System to prevent BB dropping after removing the magazine. The Latching Arm can also be manually pressed to release the remaining BB from inside the hopup chamber.

***The Dual UV LED Tracer Module is an add-on option to glow BB in the dark. Operating Voltage from 7VDC - 15VDC (2-4 cells LiPo, 6-13 cells NiCad). (Sold separately)
***Test results: FPS might be increased from 10FPS to 30FPS over the stock setup. Please check your FPS!

 

  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

 

  Specification
Overall Length: 51.65mm
Overall Height: 38.75mm
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
Material: Aluminum 6061

 

  Features
Machined from a solid aircraft aluminum block with tight tolerances to achieve the most accuracy, consistency, and durability
Performed accurately and consistently on ICS CXP/CS4/EBB (include old models) M4/M16 AEG series
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 21.00mm to 21.25mm 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 OD12mm to ensure the hopup unit is inserted exactly in the center of the 12mm inner bore ICS AEG Gearbox nozzle outlet without wobbling. (Inlet Adaptor OD11mm and OD11.5mm 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
Specially designed with a new BB Latching System to prevent BB dropping after removing the magazine
The Latching Arm can also be manually pressed to release the remaining BB from inside the hopup chamber
Compatible with any 12mm inner bore ICS AEG Gearbox nozzle outlets
The Dual UV LED Tracer Module to glow BB in the dark ready!

 

  Weight
N/A grams

 

  Usage
Compatible with most ICS CXP/CS4/EBB (include old models) M4/M16 AEG series

 

  Requires
Wearing eye protection is recommended
Use proper tools for disassembly and reassembly the gear box with great care due to spring tension
Bearing lubricant oil/grease is recommended for smooth operation

 

  Instruction
Instruction Manuals are included

 

ICS® is a registered trademark of ICS Enterprise Co., Ltd.

 

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 39855183500

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.4 ★★★★★
Based on 2285 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
G
Verified Purchase
Grma4m&m
Phoenix, US
★★★★★ 5
They’re fantastic!!!!
Size: X-Large, Color: Multicoloured E-(5-pack)
My clothing size is 16/18 and XL. Even though Amazon suggested a size XXL, I ordered my normal XL and they fit perfectly. The fabric for this style is 92% bamboo viscose and is amazingly soft and almost silky feeling. I had ordered a different boy short in this brand but they were 80% bamboo viscose and the fabric was significantly heavier. I returned those and ordered these.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 25, 2026
L
Verified Purchase
Liz Newman
Boise, US
★★★★★ 5
Comfortable and cool. Does not ride up.
Color: 01-multicolour (4-pack), Size: Medium
Extremely comfortable. Stays cool. Ample coverage. Quality material. They do not creep up. I ordered a medium which I generally take a size small. I have reordered and will reorder again to add more colors to my collection.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 18, 2026
J
Verified Purchase
Janola
Birmingham, US
★★★★★ 5
Great Value for Cool Thigh Protection
Color: 02-multicolour (4-pack), Size: XX-Large
For the price, I'm not sure there are better women's boxer shortlettes anywhere. I've tried more expensive brands, and for quality and cooling, these are right up there. I have other bamboo viscose undies that still get gross when I get sweaty in the summer, but these, with the large mesh panel, really help wick away a lot of that moisture, keeping you feeling dryer and cooler. I find that the leg openings are comfortable and don't roll up! and the waist band doesn't dig, nor does it roll down. These do not provide any compression, and I wasn't looking for any. I just wanted some cooling, thigh protecting women's boxers that wouldn't break the bank. These are them! Bonus- I've washed them and put them in the dryer (following their instructions), and they haven't shrunk; they look about the same and are nice and soft.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 28, 2025
R
Verified Purchase
Reviewer
Port Orchard, US
★★★★★ 4
Great for the entire family but expensive
So far so good. The brand of boxers we had been buying changed their style and construction so we needed to find an alternative. These have held up well so far to multiple weeks of frequent washing and wearing from the entire family. We did size up from the usual 6/M we normally buy and ordered large to prevent the legs from rolling up which worked out great. Our daughter likes the length and how soft the fabric is for wearing under skirts and gym shorts and liners stay put without moving or leaking as another reviewer mentioned. Our son says they are comfortable and fit well being just supportive enough without being constrictive. We all agree that there seems to be not enough fabric in the back as they tend to be much tighter across the backside than the front and that also causes the waist band to ride lower in the back than the front. These have better seam placement than some brands we tried with no seam across the lady bits and no seam down the middle of the back side so they are more much comfortable but the cost is also much higher and that is why we're only giving it 4 stars. These will stay in the rotation until we find something cheaper that both us and the kids like.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on January 24, 2026
B
Verified Purchase
Brittany
San Leandro, US
★★★★★ 5
Pregnant lady review! Soft, comfortable, cool.
Color: 03-multicolour (4-pack), Size: Large
So soft, comfortable and cool. I'm pregnant and I've gained weight in my legs. I love wearing dresses but my thighs were rubbing together too much. These are perfect to wear under dresses. I also wear them under my bibs at work and it keeps me from getting overheated but I don't have to worry about whether or not my underwear show since they just look like shorts. I wish these came in maternity. I just keep them below my belly. I'll be buying more for sure.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 8, 2026

recommand products