{"product_id":"lewmar-50mm-synchro-block-single-becket-990-lb-working-load-limit-1-4-3-8-inch-line","title":"Lewmar 50mm Synchro Block Single Becket, 990 lb Working Load Limit, 1\/4 - 3\/8 Inch Line","description":"\u003cp\u003eThe Lewmar 50mm Synchro Block Single Becket is a sailboat block built for efficient line handling on halyards, mainsheet systems, mast foot and head applications, and boom vangs. It uses a 50mm sheave with a 990 lb working load limit and accommodates line diameters from 1\/4 inch to 3\/8 inch, making it suited to a wide range of small to mid-size sailboat rigging setups.\u003c\/p\u003e\u003cp\u003eThe block's geometry and larger sheave diameter are engineered to minimize rope friction, while a high-density Free-Spin bearing reduces axle diameter to cut friction further and boost overall efficiency compared to standard budget blocks. A self-aligning head keeps the block synchronized with the rope's movement for smoother power transfer and reduced rope wear during use. The single becket design provides a fixed attachment point for tying off a line, useful in multi-part purchase systems.\u003c\/p\u003e\u003cp\u003eConstruction pairs stiff, glass fiber reinforced cheeks, which help prevent lines from wedging, with a stainless steel strap for added strength and long-term durability in a marine environment. The block allows an easy switch between swiveling and fixed shackle configurations, and its shackle post is designed for compatibility with Lewmar traveler systems. The complete unit includes one block with becket, ready to install on compatible sailboat hardware.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand:\u003c\/strong\u003e Lewmar\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number:\u003c\/strong\u003e 29925004BK\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct Name:\u003c\/strong\u003e 50mm Synchro Block Single Becket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSheave Diameter:\u003c\/strong\u003e 50mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWorking Load Limit:\u003c\/strong\u003e 990 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLine Diameter Range:\u003c\/strong\u003e 1\/4 inch - 3\/8 inch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBearing Type:\u003c\/strong\u003e High-density Free-Spin bearing\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBecket:\u003c\/strong\u003e Single becket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShackle Configuration:\u003c\/strong\u003e Switchable between swiveling and fixed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCheek Material:\u003c\/strong\u003e Glass fiber reinforced\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStrap Material:\u003c\/strong\u003e Stainless steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor:\u003c\/strong\u003e Multi\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Items:\u003c\/strong\u003e 1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncluded Components:\u003c\/strong\u003e Block\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackage Dimensions:\u003c\/strong\u003e 5.75 x 2.56 x 1.38 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 0.9 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUPC:\u003c\/strong\u003e 743683203756\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eWhat line diameter fits the Lewmar 29925004BK Synchro Block?\u003c\/strong\u003e The Lewmar 50mm Synchro Block Single Becket (29925004BK) accommodates line diameters from 1\/4 inch to 3\/8 inch.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the working load limit of this Lewmar block?\u003c\/strong\u003e The 29925004BK Synchro Block has a working load limit of 990 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eDoes this block have a becket?\u003c\/strong\u003e Yes, the Lewmar 29925004BK is a single becket version, providing a fixed tie-off point for a line.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCan the shackle be switched between swiveling and fixed?\u003c\/strong\u003e Yes, the Lewmar Synchro Block 29925004BK allows an easy switch between swiveling and fixed shackle configurations.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is the sheave diameter on the 29925004BK block?\u003c\/strong\u003e The sheave diameter is 50mm on this Lewmar Synchro Block.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat materials is the Lewmar Synchro Block made from?\u003c\/strong\u003e Glass fiber reinforced cheeks are paired with a stainless steel strap on the 29925004BK, combining stiffness at the cheeks with added strength from the steel strap.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eIs this block compatible with Lewmar traveler systems?\u003c\/strong\u003e Yes, the 29925004BK shackle post is designed for compatibility with Lewmar traveler systems.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat sailing applications is this block suited for?\u003c\/strong\u003e Halyard tuning, mainsheet systems, mast foot and head blocks, and boom vangs are typical applications for the Lewmar 50mm Synchro Block Single Becket.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow does the Free-Spin bearing improve performance?\u003c\/strong\u003e The high-density Free-Spin bearing in the 29925004BK reduces axle diameter, which lowers friction and improves efficiency compared to standard budget blocks.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat is included when I order the 29925004BK?\u003c\/strong\u003e One Lewmar 50mm Synchro Block Single Becket is included, ready to mount to compatible sailboat hardware.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eHow much does the Lewmar 29925004BK block weigh?\u003c\/strong\u003e The Lewmar 29925004BK Synchro Block weighs 0.9 pounds.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy do the block cheeks matter for line handling?\u003c\/strong\u003e The glass fiber reinforced cheeks on the 29925004BK are stiff enough to help prevent lines from wedging between the sheave and cheek during use.\u003c\/p\u003e","brand":"Lewmar","offers":[{"title":"Default Title","offer_id":49025132527835,"sku":"LEW-29925004BK","price":31.78,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0839\/7586\/4539\/files\/LEW-29925004BK__80924.1722376448.500.750.jpg?v=1785329116","url":"https:\/\/www.goodvibesmarina.com\/products\/lewmar-50mm-synchro-block-single-becket-990-lb-working-load-limit-1-4-3-8-inch-line","provider":"Good Vibes Marina","version":"1.0","type":"link"}