SKU: 51161598334

Fusion Engine™ Drop-In Kit

Sale price$237.15 Regular price$263.50
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Ships within 48 hours · Estimated delivery Jul 22 - Jul 27

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Description

Fusion Engine™ Drop-In KitThe Original HPA Rebel The Fusion Engine was released in 2011 and was the first new HPA system to hit the airsoft market in over two decades. This is the system that started the HPA revolution and has set the benchmark to which all other systems are measured. Although many have followed it, the Fusion Engine is considered by most to be the best. This system won "Best HPA Engine" the very first year Popular Airsoft added the HPA class to their Players'

 The Original HPA Rebel

The Fusion Engine™ was released in 2011 and was the first new HPA system to hit the airsoft market in over two decades. This is the system that started the HPA revolution and has set the benchmark to which all other systems are measured. Although many have followed it, the Fusion Engine™ is considered by most to be the best. This system won "Best HPA Engine" the very first year Popular Airsoft added the HPA class to their Players' Choice Awards.


This is a complete drop-in system which replaces the entire AEG gearbox with a full CNC machined lightweight aluminum chassis. It is the most adjustable system we produce with the widest range of adjustment in both velocity and rate of fire. Being a dual solenoid, closed bolt system so you are able to adjust the poppet valve (firing air) and nozzle (feeding) independently for full control over both the loading time and air volume used. PolarStar Filter Fitting included.


Being a true closed bolt system it is easier to achieve a high level of accuracy since it is not as critical of the hop-up configuration as an open bolt system. Additionally, it does have the best feeling trigger since the trigger micro-switch is custom fit to the frame so the trigger has a distinct break, hard stop and short reset.



 

Gel Ball Compatible 

Fusion Engine HPA conversion kits can also be configured for use in gel ball systems.

Please contact us for information on ordering Fusion Engine  systems for gel ball use.

 

 

 

 

Velocity: 550fps w/ .20g @ 120psi.
Like other HPA systems, the velocity of the Fusion Engine™ can be fine tuned by adjusting the input pressure. However, there are also 6 nozzles available each with a different level of restriction which allows you to shift the velocity adjustment range up or down in large increments. This allows the Fusion Engine™ to have the widest velocity adjustment range of any of our systems.
ROF: 30rps+
The maximum cyclic rate of the Fusion Engine™ is affected by several factors such as the operating pressure as well as the quality of the magazine and BB's used. However, 30 rounds per second is achievable in most standard configurations.
Air Efficiency: 400+ shots from 13/3000 @ 1.5J  w/ .28g
This system was primarily designed to deliver maximum power so air efficiency was not a critical part of its development. However, thanks to the modular design of its poppet valve, the system can be fine tuned using more restrictive valve stems and shims which allows air efficiency to more than double when operating at traditional field velocities.
(Test Configuration: Black Poppet / Blue Nozzle / 6.05x375mm Barrel)

 


**All kits come with a Filter Fitting installed, FCU, Switchboard, Wire Harness and any additional components needed to convert the specific airsoft rifle model for which the kit is configured. The HPA Tank, Air Rig (regulator and line) and Battery needed to operate the system are purchased separately.**

 

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: 51161598334

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Glass
Lake Worth, US
★★★★★ 5
I stay on your foot they don’t slip in your shoe
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
This is the only socks I wear Under Armour because they stay in place I wear a size 8, but they’re more comfortable with a large instead of a medium, but I wear both because I have them already and you can pull them to stretch them out a little bit
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Reviewed in the United States on May 12, 2026
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Lauren
Grantham, US
★★★★★ 5
Great fit, truly doesn’t slide off heel
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium, Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
I’ve scoured all the lands looking for a no-show sock that was 1) thin, 2) quality, soft, breathable material, 3) didn’t dig into my feet/heels, 4) doesn’t shrink, and most importantly 5) stays on the back of my heel without a bulky non-slip rubber piece and these check all the boxes! Perfect for low profile women’s work shoes like Keds, etc. Not low enough for most flats though. I wear a women’s size 9.
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Reviewed in the United States on April 19, 2025
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Elliz
Grantham, US
★★★★★ 5
So good - I’m buying MORE.
Number of Items: 3, Color: White (3-pairs), Size: Medium
I’m gonna give you more detail than you need about why I’m buying these socks again. I’ve been the mom of girl athletes. I’ve been a model and a fashion director. I’ve worn every brand of shoe on the planet and never found a shoe that did NOT find a vulnerable spot on my foot to rub raw. Even my beloved white Jack Purcell sneakers. With that said - I don’t like socks. I’ve bought a TON of them in 35+ years.....all major brands. They shift. They lose their shape. They get holes in them and wear out too fast. Not these. I retired this year, and knowing I’d be in sneakers a lot, traveling, sightseeing ...... I bought these 6 months ago and have worn them constantly. I’ve traveled with them. I’ve washed them in hot water and bleach. The socks are like brand new. They are exactly the right cut so as not to be seen in a basic sneaker. The little silicone patch on the heel stays put. Not once have I had to dig down into my shoe and pull the sock back up. The socks have stayed soft and EXACTLY the same as the day they were new. Like I said - I am back to buy them again. Great quality!
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Reviewed in the United States on January 20, 2021
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Judy Fletcher
Lake Worth, US
★★★★★ 5
No slip low socks
Number of Items: 3, Color: Black/White (3-pairs), Size: Medium
Perfect! ❤️ these!
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Reviewed in the United States on February 16, 2026
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Susan
Pawtucket, US
★★★★★ 4
Stay put!
Number of Items: 3, Color: White/Neutral (3-pairs), Size: Medium
Nice and thin, soft, and stay put. I wear an 8 shoe and don’t like a thick sock taking up room. These socks are a bit tight on big toe. Wish they came in large.
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Reviewed in the United States on October 10, 2023

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