{"product_id":"lewmar-50mm-synchro-block-halyard-black-1-4-3-8-line-239-29925021","title":"Lewmar 50mm Synchro Halyard Block – Black, 1\/4”–3\/8” Line","description":"\u003ch2\u003eClean Halyard Runs, Minimal Friction\u003c\/h2\u003e\u003cp\u003eThe Lewmar 50mm Synchro Halyard Block is purpose-built for halyard applications where a low-friction, fixed-head block keeps lines running straight and true from the masthead to the clutch or winch. Its high-density, free-spin plain bearing delivers smooth operation under load, while the patented shackle post lock makes mast attachment fast and secure without tools.\u003c\/p\u003e\u003cp\u003eBuilt with stainless steel straps and glass-fibre reinforced cheeks, the Synchro series handles the demands of performance sailing while keeping overall weight to a minimum. Sheave, bearing, pin, and line size are matched for optimum efficiency across the 1\/4”–3\/8” line range.\u003c\/p\u003e\u003ch3\u003eCompatible Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eMain and jib halyard lead blocks at the mast base\u003c\/li\u003e\n\u003cli\u003eSpinnaker halyard turning blocks\u003c\/li\u003e\n\u003cli\u003eFixed-head halyard routing on performance sailboats\u003c\/li\u003e\n\u003cli\u003eLine sizes: 1\/4” to 3\/8” (6–8mm)\u003c\/li\u003e\n\u003cli\u003eBlock size: 50mm sheave diameter\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eProduct Details\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eConfiguration: Halyard (fixed head)\u003c\/li\u003e\n\u003cli\u003eSheave diameter: 50mm\u003c\/li\u003e\n\u003cli\u003eLine range: 1\/4”–3\/8” (6–8mm)\u003c\/li\u003e\n\u003cli\u003eColor: Black\u003c\/li\u003e\n\u003cli\u003eBearing: High-density free-spin plain bearing\u003c\/li\u003e\n\u003cli\u003eConstruction: Stainless steel straps, glass-fibre reinforced cheeks\u003c\/li\u003e\n\u003cli\u003eAttachment: Patented shackle post lock\u003c\/li\u003e\n\u003cli\u003eSKU: 239-29925021\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eParts Desk Insights\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eBest Use Case:\u003c\/strong\u003e The halyard block is the right choice when you need a fixed-head block that stays aligned with the halyard run — typically at the mast base or on a turning point where a swivel head would add unnecessary complexity. The 50mm size is ideal for smaller performance sailboats and dinghies where keeping weight aloft is a priority. Step up to the \u003ca href=\"\/products\/lewmar-60mm-synchro-halyard-block-black-29926021\"\u003e60mm Synchro Halyard Block\u003c\/a\u003e for heavier loads or larger line sizes.\u003c\/p\u003e\u003ch3\u003eOther 50mm Synchro Blocks\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-single-black-1-4-3-8-line-239-29925001bk\"\u003e50mm Synchro Block – Single, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-synchro-block-double-black-1-4-3-8-line-239-29925002bk\"\u003e50mm Synchro Block – Double, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-synchro-block-triple-black-1-4-3-8-line-239-29925003\"\u003e50mm Synchro Block – Triple, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-single-black-1-4-3-8-line-239-29925004\"\u003e50mm Synchro Block – Single w\/Becket, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-double-block-becket-black-29925005bk\"\u003e50mm Synchro Block – Double w\/Becket, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-single-w-becket-cam-black-1-4-3-8-line-239-29925009\"\u003e50mm Synchro Block – Single w\/Becket \u0026amp; Cam, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-triple-w-becket-cam-black-1-4-3-8-line-239-29925010\"\u003e50mm Synchro Block – Triple w\/Becket \u0026amp; Cam, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-fiddle-w-becket-black-1-4-3-8-line-239-29925034\"\u003e50mm Synchro Block – Fiddle w\/Becket, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-50mm-synchro-block-fiddle-w-cam-black-1-4-3-8-line-239-29925037\"\u003e50mm Synchro Block – Fiddle w\/Cam, Black\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOther Synchro Block Sizes\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-60mm-synchro-block-single-black-5-16-3-8-line-239-29926001bk\"\u003e60mm Synchro Blocks – 5\/16”–3\/8” Line\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-72mm-synchro-block-single-black-3-8-1-2-line-239-29927201\"\u003e72mm Synchro Blocks – 3\/8”–1\/2” Line\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/lewmar-90mm-synchro-block-single-w-becket-black-1-2-9-16-line-239-29929004\"\u003e90mm Synchro Blocks – 1\/2”–9\/16” Line\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003ePair It With\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e\u003ca href=\"\/products\/lewmar-synchro-snap-shackle-239-29925040\"\u003eLewmar Synchro Snap Shackle – 50mm\u003c\/a\u003e\u003c\/li\u003e\u003c\/ul\u003e","brand":"LNS","offers":[{"title":"Default Title","offer_id":51250739937316,"sku":"239-29925021","price":51.0,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0743\/5799\/7604\/files\/9d8bed5b-9fcf-46a3-8ef9-6aab066e474a.png?v=1787026411","url":"https:\/\/marisolmarine.com\/products\/lewmar-50mm-synchro-block-halyard-black-1-4-3-8-line-239-29925021","provider":"Marisol Marine Company","version":"1.0","type":"link"}