{"product_id":"m-1243-57-p-or-bi-bs45-b70","title":"BS 4518 1243-57 Buna-N Nitrile (70A) Metric O-Ring, 70A Durometer, 124.3mm ID x 5.7mm CS (4.894\" x 0.224\", 135.7mm OD) - Precision-Molded Replacement Sealing Ring for Pumps, Valves \u0026 Fittings","description":"\u003cp\u003eChasing a leak or a slow drip and need the exact metric o-ring size to seal it for good? A worn or wrong-size o-ring lets fluid weep past the joint, drops pressure, and can damage the equipment around it.\u003c\/p\u003e\u003cbr\u003e\u003cp\u003eThis Beaver Island Parts Company replacement o-ring is a single BS 4518 1243-57 o-ring, a standard metric sealing size measuring 124.3mm inside diameter by 5.7mm cross-section (4.894\" ID x 0.224\" CS, 135.7mm outer diameter), molded in 70A Buna-N Nitrile rubber.\u003c\/p\u003e\u003cbr\u003e\u003cb\u003eFull Compatibility:\u003c\/b\u003e BS 4518 1243-57 is an international-standard o-ring size used across pumps, valves, filters, fittings and machinery worldwide. If your application calls for a 124.3mm x 5.7mm o-ring, this is the size.\u003cbr\u003e\u003cb\u003eInstallation Note:\u003c\/b\u003e Clean the groove, inspect the sealing surface, seat the new o-ring without twisting it, and lubricate before assembly.\u003cbr\u003e\u003cb\u003ePro Tip:\u003c\/b\u003e Apply \u003ca href=\"https:\/\/beaverislandparts.com\/products\/aqua-flex-food-grade-silicone-lubricant-50g\" target=\"_blank\" rel=\"noopener\"\u003eAqua Flex\u003c\/a\u003e lubricant before installation to ease seating and extend seal life.\u003cbr\u003e\u003cp\u003eWe are an American family-owned and operated small business committed to high-quality replacement parts and honest fitment information.\u003c\/p\u003e","brand":"Beaver Island Parts Company","offers":[{"title":"1 (Single)","offer_id":48609968324813,"sku":"M.1243-57.1.OR.BI.BS45.B70","price":9.99,"currency_code":"USD","in_stock":true},{"title":"5-Pack","offer_id":48609968357581,"sku":"M.1243-57.5.OR.BI.BS45.B70","price":16.99,"currency_code":"USD","in_stock":true},{"title":"10-Pack","offer_id":48609968390349,"sku":"M.1243-57.10.OR.BI.BS45.B70","price":24.99,"currency_code":"USD","in_stock":true},{"title":"25-Pack","offer_id":48609968423117,"sku":"M.1243-57.25.OR.BI.BS45.B70","price":50.99,"currency_code":"USD","in_stock":true},{"title":"50-Pack","offer_id":48609968455885,"sku":"M.1243-57.50.OR.BI.BS45.B70","price":83.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0611\/8110\/0237\/files\/AS568-352_fb729324-d4d1-48ea-a20e-4a76876fb02b.png?v=1785883017","url":"https:\/\/beaverislandparts.com\/products\/m-1243-57-p-or-bi-bs45-b70","provider":"Beaver Island Parts Company","version":"1.0","type":"link"}