{"product_id":"polarstar-direct-attachment","title":"PolarStar Direct Attachment — F2 and JACK Front Cylinder","description":"\u003cdiv style=\"background:#edfaf1;border-left:4px solid #27ae60;padding:12px 16px;border-radius:0 6px 6px 0;margin:0 0 16px;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#1a6b3a;\"\u003ePolarStar Direct Attachment.\u003c\/strong\u003e A replacement front cylinder for the F2 or the JACK that lets the engine thread straight into the Hop Up Thing. Engine, hop unit and inner barrel end up as one rigid assembly, so the nozzle cannot sit crooked in the bore.\n\u003c\/div\u003e\u003cp\u003eOn a conventional build the upper gearbox shell is what holds the engine in line with the hop unit. That is a lot of responsibility for a moulded or cast shell, and it is why people lose evenings to shimming: half a millimetre of nozzle tilt is enough to spoil a grouping, and you cannot see it from the outside.\u003c\/p\u003e\u003cp\u003eThis removes the shell from that job entirely. It is a two-piece set — a front cylinder that replaces the original on your engine, plus an internal adapter — and the Hop Up Thing screws directly into it. Once it is together the engine, the hop unit and the inner barrel are a single rigid piece of metal. There is nowhere for the nozzle to lean as it loads a round, which means each BB is picked up the same way, which is where consistent hop and tighter groups actually come from.\u003c\/p\u003e\u003cp\u003eAlignment stops being something you chase and becomes a property of the parts. PolarStar's own framing is blunt about it: with the thread done up, it is not physically possible for the nozzle to be out of line with the bore.\u003c\/p\u003e\u003cp\u003eWhat you still need is somewhere to put the electronics. Because the upper shell is no longer doing any aligning, you can house the trigger, selector and wiring in a modified shell, a printed lower or a fully custom chassis — PolarStar built this with scratch builds and 3D-printed projects in mind as much as fixing an existing gun. It is a building block, not a drop-in.\u003c\/p\u003e\u003ch2 style=\"font-size:16px;color:#1B3A6B;margin:18px 0 8px;\"\u003eSpecifications\u003c\/h2\u003e\u003ctable style=\"width:100%;border-collapse:collapse;font-size:13px;margin:0 0 18px;\"\u003e\n\u003ctr style=\"background:#1B3A6B;color:#fff;\"\u003e\n\u003cth style=\"padding:7px 12px;text-align:left;\"\u003eSpecification\u003c\/th\u003e\n\u003cth style=\"padding:7px 12px;text-align:left;\"\u003eDetail\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eFunction\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eReplaces the front cylinder on an F2 or JACK engine\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eSupplied as\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eDirect attach front cylinder plus internal adapter\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eEngine fitment\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eF2 or JACK, matched to the version you choose\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eHop unit interface\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eThreads directly to the PolarStar Hop Up Thing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eResult\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eEngine, hop unit and inner barrel form one rigid assembly\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eGearbox shell\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eNo longer required for alignment; still needed to house electronics\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f5f5f5;\"\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eNot included\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eEngine, hop unit, gearbox shell or chassis, inner barrel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003eBrand\u003c\/td\u003e\n\u003ctd style=\"padding:7px 12px;border:1px solid #eee;\"\u003ePolarStar\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch2 style=\"font-size:16px;color:#1B3A6B;margin:18px 0 8px;\"\u003eGood to know\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eWhich one do I need?\u003c\/strong\u003e Match it to your engine — the F2 version for an F2, the JACK version for a JACK. They are not interchangeable.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes it come with the hop unit?\u003c\/strong\u003e No, and it does nothing without one. It is designed around the \u003ca href=\"\/products\/polarstar-hop-up-thing\" style=\"color:#1B3A6B;\"\u003ePolarStar Hop Up Thing\u003c\/a\u003e, which is a separate purchase.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDo I still need a gearbox shell?\u003c\/strong\u003e Not for alignment, but the trigger, selector and electronics have to live somewhere. A modified shell, a printed lower or a custom chassis all work.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWill this work in a normal rifle?\u003c\/strong\u003e Yes. Plenty of people fit it to a standard build simply to cure a shell that will not hold alignment.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs it a performance part or an engineering part?\u003c\/strong\u003e Both, but the gain is indirect: it does not add power, it removes the movement that was costing you consistency.\u003c\/p\u003e\u003cdiv style=\"background:#fffbe6;border-left:4px solid #f0d060;padding:12px 16px;border-radius:0 6px 6px 0;margin:0 0 16px;font-size:13px;\"\u003e\n⚠ \u003cstrong\u003eThis is a builder's component:\u003c\/strong\u003e it assumes you are willing to work out a home for the trigger and electronics. If you want a conversion that simply drops into an existing gun, a standard engine kit is the better buy.\n\u003c\/div\u003e\u003cdiv style=\"background:#1B3A6B;color:#fff;padding:12px 16px;border-radius:6px;margin:18px 0 0;font-size:13px;\"\u003e\n\u003cstrong style=\"color:#fff;\"\u003e💡 Titan Forge Airsoft tip:\u003c\/strong\u003e Thread it onto the \u003ca href=\"\/products\/polarstar-hop-up-thing\" style=\"color:#cdd6f4;\"\u003eHop Up Thing\u003c\/a\u003e and feed it from our \u003ca href=\"\/collections\/hpa-accessories\" style=\"color:#cdd6f4;\"\u003eHPA accessories\u003c\/a\u003e range. The rest of the brand sits in \u003ca href=\"\/collections\/polarstar\" style=\"color:#cdd6f4;\"\u003ePolarStar\u003c\/a\u003e.\n\u003c\/div\u003e","brand":"Polarstar","offers":[{"title":"F2","offer_id":55696832495992,"sku":"51490496","price":29.95,"currency_code":"GBP","in_stock":false},{"title":"JACK","offer_id":55696832528760,"sku":null,"price":32.95,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0562\/8097\/3450\/files\/PolarStarDirectAttachmentF2_JACK_TitanForgeAirsoft.webp?v=1791726982","url":"https:\/\/www.titanforgeairsoft.com\/products\/polarstar-direct-attachment","provider":"Titan Forge Airsoft","version":"1.0","type":"link"}