SKU: 99206998798

Polarstar JACK HPA Conversion Kit

$137.22 $152.47
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Ships within 48 hours · Estimated delivery Jul 16 - Jul 21

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Description

Polarstar JACK HPA Conversion KitWe can custom anodize your Jack in the colors you want for $100 more. 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. Code Name "Simple Jack" The JACK was designed to answer the demand for an

We can custom anodize your Jack in the colors you want for $100 more.

Code Name "Simple Jack"

The JACK™ was designed to answer the demand for an affordable, high performance HPA (High Pressure Air) conversion for AEG's. The system is a drop-in cylinder replacement that is universally compatible with a wide range of gearbox versions that have center-line nozzles. PolarStar Filter Fitting now included!

Similar to its sister products, the JACK™ replaces the original gearbox components with a programmable pneumatic system allowing for higher performance and greater reliability over a gear driven system. Although economically priced, the JACK™ still retains the same performance and quality you have come to expect from PolarStar products.

The JACK™ has only one moving part, the nozzle, which acts as its own poppet valve. Similar to the Fusion Engine™ and F2™ poppet, the nozzle is only piloted by the solenoid to open air flow through the poppet with none of the firing air coming from the solenoid itself. This design lets the JACK™ send a higher flow of air down the barrel than systems that only use a solenoid as the firing valve.

Gel Ball Compatible

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

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

Velocity: 500fps w/ .20g @ 130psi
The JACK™ allows for easy velocity adjustment by changing input pressure and does not require different nozzles to reach its full velocity range. Using a standard M4 as an example, velocity can be adjusted from below 280fps and up to approximately 500fps with a .20g BB. Velocity can vary per model as longer barrels will increase the maximum velocity while shorter barrels will decrease it. 
ROF: 30rps
The maximum cyclic rate of the JACK™ is affected by several factors such as the operating pressure as well as quality of the magazine and BB's used. However, 30 rounds per second is achievable in most standard configurations.
Air Efficiency: 1000+ shots from 13/3000 @ 1.5J  w/ .28g
Although not a critical requirement during development, JACK™ does boast some highly respectable figures in this category. This is made possible by its intelligently laid out design which minimizes dead volume resulting in better air flow, faster response and less air used per shot.
(Test Configuration: 6.05x375mm Barrel)
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: 99206998798

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4.8 ★★★★★
Based on 24 reviews
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Verified Purchase
Aimee C.
Whiting, US
★★★★★ 4
Perfect size and weight with compact size
Style: Rack with 3 Pairs (3, 5, and 8 Pound)
I purchased the Amazon Basics Neoprene Dumbbell Hand Weights specifically for Pilates, and they’ve been a great addition to my routine. The size and weight are perfect for controlled movements, helping with muscle toning without feeling too bulky or awkward. The neoprene coating gives them a comfortable, non-slip grip, which is especially important during longer sessions or when your hands get a little sweaty. They feel secure and easy to hold through a full workout. I also like the shape—they don’t roll around on the floor, which makes transitions between exercises smoother and less frustrating. They’re compact enough to store easily but still feel durable and well-made. Overall, these are a simple, affordable, and effective option for Pilates or light strength training. I’d definitely recommend them for anyone looking to add a little resistance to their workouts without overcomplicating things.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 20, 2026
J
Verified Purchase
J. saroukhan
Battle Creek, US
★★★★★ 5
Well made , gym quality
Style: 10 Pound, Pair
Color is nice and bright . The weights grips are good they do not slip . Prices reflect quality
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Reviewed in the United States on May 29, 2026
K
Verified Purchase
Kim Wood
Belleville, US
★★★★★ 5
Good purchase
Style: 3 Pound, Pair
These are just the right weight for me to start gaining muscle back in my arms, after a large weight loss. They are of good quality, they are covered in a nice rubber like coating that is soft to the touch. They are small enough that i can take them with me when I travel. My dog has got hold of them a couple times and played with them, and they held up just fine without any damage.
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Reviewed in the United States on April 28, 2026
K
Verified Purchase
Ky Mogg
Lowell, US
★★★★★ 5
Solid, grippy, and they don’t roll away!
Style: 10 Pound, Pair
I bought these because I’m finally trying to build a consistent home workout routine and didn't want to drop a fortune on name-brand weights. I’ve been using this 10lb pair for about a month now for everything from overhead presses to lunges, and honestly, they’re exactly what I was looking for. The Pros: • That Neoprene Grip: The coating is fantastic. Even when my hands get pretty sweaty halfway through a workout, I don’t feel like I’m going to drop them. It’s a much "softer" feel than cold metal or hard plastic. • The Hex Shape: This is a small detail that makes a huge difference. Since the ends are hexagonal, they don't roll across the floor when I set them down between sets. They also stay put if I’m using them for "renegade rows" or floor work. • Compact Size: They aren’t bulky. I can easily shove them under my bed or in the corner of the closet when I’m done. • No Weird Odor: I was worried they might smell like a tire factory (which happens with some rubber-coated weights), but these had almost no scent right out of the box. The Cons: • Handle Diameter: The handles are a little on the thicker side. I have medium-sized hands and it’s fine, but if you have very small hands, they might feel a bit chunky to wrap your fingers all the way around. • Color Scuffs: The navy blue looks great, but if you clank them together or drop them on concrete, the coating can scuff or show dust pretty easily. The Verdict: If you just need a reliable set of weights for HIIT, Pilates, or general strength training, these are a no-brainer. You're basically getting gym-quality equipment for a fraction of the price. I’ll probably be back for the 15lb set in a few months!
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Reviewed in the United States on January 27, 2026
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Verified Purchase
Matt
New York, US
★★★★★ 5
Simple, Comfortable, and Exactly What You Expect
Style: Rack with 3 Pairs (5, 10, and 15 Pound)
These are pretty much exactly what you want from a set of dumbbells — simple, functional, and no nonsense. The neoprene coating gives them a comfortable grip and keeps them from feeling slick in your hands, especially during longer workouts or if your hands get sweaty. The coating also helps keep them from banging up floors or making as much noise compared to bare metal weights, which is nice if you’re working out at home. Weight accuracy seems fine for general fitness use, and they’ve worked great for things like accessory movements, shoulder work, lighter presses, rehab-style exercises, and general muscle toning. The shape also helps keep them from rolling around everywhere when set down. They’re not fancy, and they’re not trying to be — they’re just dependable dumbbells that do what they’re supposed to do at a fair price. If you want straightforward hand weights for home workouts without overthinking it, these are a solid buy.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 26, 2026

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