{"product_id":"polarstar-jack-hpa-kit","title":"PolarStar JACK™ HPA Conversion Kit","description":"\u003cp\u003eCode name \"Simple Jack.\" The JACK™ was designed to answer demand for an affordable, high-performance HPA conversion for AEGs — a drop-in cylinder replacement universally compatible with a wide range of gearbox versions that have center-line nozzles. PolarStar Filter Fitting included.\u003c\/p\u003e\n\n\u003cp\u003eThe JACK™ has only one moving part: the nozzle, which acts as its own poppet valve. Like the Fusion Engine™ and F2™, the nozzle is only piloted by the solenoid to open airflow — none of the firing air comes through the solenoid itself. This lets the JACK™ deliver higher flow down the barrel than solenoid-only firing valve designs.\u003c\/p\u003e\n\n\u003ch4\u003eGel Ball Compatible\u003c\/h4\u003e\n\u003cp\u003eJACK kits can be configured for gel ball systems. Contact us for details.\u003c\/p\u003e\n\n\u003ch4\u003ePerformance\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eVelocity:\u003c\/strong\u003e Up to 500fps w\/ .20g @ 130psi — full range adjustable by pressure alone with no nozzle change\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eROF:\u003c\/strong\u003e 30rps in most standard configurations\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAir Efficiency:\u003c\/strong\u003e 1000+ shots from 13\/3000 @ 1.5J w\/ .28g\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMinimized dead volume\u003c\/strong\u003e for better airflow, faster response, and less air per shot\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"PolarStar","offers":[{"title":"V2, M4\/M16","offer_id":45868775735330,"sku":"10000395","price":332.0,"currency_code":"USD","in_stock":true},{"title":"V3, AK","offer_id":45868775768098,"sku":"10000745","price":338.0,"currency_code":"USD","in_stock":true},{"title":"M249","offer_id":45868775800866,"sku":"10000748","price":333.5,"currency_code":"USD","in_stock":true},{"title":"M60","offer_id":45868775833634,"sku":"10000754","price":338.75,"currency_code":"USD","in_stock":true},{"title":"Ares EFCS \/ APS eSE","offer_id":45868775866402,"sku":"10000792","price":338.25,"currency_code":"USD","in_stock":true},{"title":"Ares M4","offer_id":45868775899170,"sku":"10000793","price":338.75,"currency_code":"USD","in_stock":true},{"title":"VFC HK417","offer_id":45868775931938,"sku":"10000794","price":338.25,"currency_code":"USD","in_stock":true},{"title":"S\u0026T TAR-21","offer_id":45868775964706,"sku":"10000796","price":327.0,"currency_code":"USD","in_stock":true},{"title":"KAC LMG","offer_id":45868775997474,"sku":"10000798","price":329.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0741\/5355\/8050\/files\/ChatGPT_Image_Jun_19_2026_10_25_47_PM_3.png?v=1781933183","url":"https:\/\/www.katechairsoft.com\/products\/polarstar-jack-hpa-kit","provider":"KA Tech Airsoft ","version":"1.0","type":"link"}