PolarStar Airsoft JACK Electro-Pneumatic Gearbox Conversion Kit (Model: V2 M4 / M16)

"Used in over 10 sessions at my indoor field. Not problems whatsoever. Great budget HPA engine.

Pros:
Trigger response
Reliability
Quietness
Ease of use
Programmability
Quality
Made in America
Changeable fps

Cons:
Price (This goes for basically every good HPA engine)
Does not come with 1/8 Male QD (Would recommend getting Amped IGL)

Conclusion:
Amazing HPA engine. Will last for a long time and if something does break, parts are readily available. If you don't want to constantly tech with aegs and want insane trigger response and adjustable fps, look no further.

"Had this for almost a year and a half, and no real complaints.

PROS:
Shoots like a p*
Easily shoots over 60 rps without changing fcu settings other than ROF
Can be used at any field by adjusting psi input
Pisses people off just by looks
Easy to understand FCU
Burst, if you're into that
Can be used in any gun (Threw mine into a plastic $100 lancer tactical and it worked while I slowly upgraded it)
Useable by any battery
Battery can stay plugged in for a month and never die

CONS:
Full auto switch on trigger board doesn't get activated by the selector plate (most likely my cheap gearbox)
Often times will need to have foil tape added to make it secure in the gearbox

Love shredding through mags, it works like a dream, and with the right barrel assembly can laser people from across the field. It allows any type of build, from a small PDW SBR to a DMR that shoots farther than any other gun on the field. It can also be put in most other guns simply by changing the nozzle. Overall it's really great, obviously it's pricey but it shoots well and needs barely any maintenance. Don't forget the cost of the tank and lines though as that will set you back a good bit more, but if you can afford it, it will be incredibly fun to use.

"Getting shots out to about 200ft, and hasn't broken yet, 10/10 IGN.

My Setup: Krytac MK1 CRB, ProWin Hopup, Flathopped Krytac Bucking, Modify Flathop Bucking.

"Love this engine!!! Super simple install, The FCU is the easiest i have ever used, AND the fact there is so much you can customize.. Definitely buying another for a DMR build soon!

"AMAZING AMAZING AMAZING!!! I personally had a rough time with hpa guns when I purchased the valken v12 (which is not good) and the nozzle was REALLY long!! So I returned it and 2 1/2 weeks later this baby arrived its the bet thing I have boughten so far yes boughtens a word.

Pros,
Amazing
Its FREAGIN polarstar
You look pretty awsome
Own scrubs
REALLY light
Super strong and air efficient
Built to last
Makes you look tacticool

Con
When your shooting you better have bbs on speed dial cuz this thing RIPS through bbs I went through a midcap mag in almost a minute shootin only semi.

"I got this pretty much the first batch and Its preformed pretty awesome. Here are some pros and cons. or mostly Pros..

Pros.
Fast really fast I run mine at a modest 25 30rps and it feeds and shoots great.
Ultra efficient. I shot 1500 2000 bbs and I still had almost 2000 psi in my 68 tank on 2800 psi fill. So I would assume 5000 shots from a 68 3000 psi fill.
FPS Is AWESOME. Through my Xcoretec im at 395fps with a .25 and 370fps with a .30 My choice of bb is .30 For Jack and its deadly accurate and really sends a .30 nicely.
Cons
Not easy to drop in like they say in ALL gear boxes. My Choice was a G&P and I had to dermal out 3 spots to get the fcu wire to sit not pinched.
Also getting the gear box to close with the trigger spring flying out the Spring guide falling all over the Air line out the bottom when it wants to be straight not curved down and the fcu wire to also lay out the fresh cut hole out the back is a task. 2 hands were required at that point it wasn't to bad.
Some times full auto quit working on me. I would go from semi to full and get semi on full.. Its a crap shoot but seams like its working now but im not sure why it works and sometimes wont.
I have shot this about 10,000 rounds 2 games and its still working well other then the small mishaps.
I would HIGHLY recommend getting some kind of LIGHT trigger spring set up like a speed trigger. There is NO reason to have a insanely tite trigger when you dont need it to activate the small switch. I didnt have a new lighter spring and the G&P one is way way to strong and hard to keep in place while trying to close up the box.
all in all its an Incredible item and I can tell you this calling Polarstar is almost like calling buddy's they are there to help and fix what they can. USA built. I have another in my cart right now.

"When I first got the polarstar jack I was very excited. It is an amazing system. I had no issues installing the jack into my aps spyder. The fcu readout took me a few seconds to understand. After looking at the instructions, where it explains what everything means it was a piece of cake. I have used the jack in two big events since I installed it and it has been amazing. If you are unsure about buying this product just buy it. Worth every penny.

PROS
Quick install
Fcu readout
Air efficient
Easy to use and understand.

"Love this thing! I had it working for a bit and then i had a hpa problem with it but i got it fixed. Just wished my local field didn't ban these on the weekends :c

gave it a 4/5 because of the hassle trying to get it fixed out of the box.
other than that, if i didnt have those problems
10/5

"Was pretty disappointed in this purchase. I had a couple of problems with my jack my biggest issue is with evike for not stating that it doesn't come with the wire for the box magazine. My jack also did not fire at all when first used it but then started to work I have no idea what was wrong with it. I own a regular fusion engine and honestly save another 200$ and buy the regular fusion engine however if you're on a tight budget it's okay once it starts working