{"product_id":"gmp104-extended-l-bar-prism-9-inch-coated-optical-survey-prism-for-accurate-subway-tunnel-measurements","title":"GMP104 Extended L‑Bar Prism – 9‑inch Coated Optical Survey Prism for Accurate Subway Tunnel Measurements","description":"\u003cp class=\"isSelectedEnd\"\u003e\u003cspan\u003eThe \u003cstrong\u003e\u003cspan\u003e\u003ca href=\"https:\/\/store.smtoer.com\/collections\/prism-surveying-instrument\" target=\"_blank\" rel=\"noopener\"\u003eGMP104 Extended L‑Bar Prism\u003c\/a\u003e\u003c\/span\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003cspan\u003e is a compact surveying prism designed for precision monitoring, inspection, and deformation measurement in demanding environments. Its 25.4 mm (1-inch) copper-coated prism provides a strong and reliable signal return for compatible surveying instruments.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"isSelectedEnd\"\u003e\u003cspan\u003eThe durable die-cast aluminum construction helps maintain stability during long-term use. The extended L-bar design provides flexible positioning, making the \u003cstrong\u003e\u003cspan\u003e\u003ca href=\"https:\/\/store.smtoer.com\/collections\/prism-surveying-instrument\" target=\"_blank\" rel=\"noopener\"\u003eGMP104 Extended L‑Bar Prism\u003c\/a\u003e \u003c\/span\u003e\u003c\/strong\u003e\u003c\/span\u003e\u003cspan\u003esuitable for locations where a conventional prism may be difficult to install.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWith an approximate \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003e-25 mm prism constant\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, this L-bar mini prism is a practical solution for subway tunnel measurements, structural monitoring, construction surveying, and other precision inspection work.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cimg src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0811\/2134\/5832\/files\/GMP104_Extended_L_Bar_Prism.jpg?v=1787729216\" alt=\"GMP104 Extended L‑Bar Prism\"\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003ePackage Includes\u003c\/span\u003e\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003e1 × L-Bar Mini Prism\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e1 × Soft Carrying Bag\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2\u003e\u003cspan\u003eSpecifications\u003c\/span\u003e\u003c\/h2\u003e\n\u003ctable height=\"324\" style=\"width: 100%;\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003cth style=\"width: 29.0044%;\"\u003e\u003cspan\u003eSpecification\u003c\/span\u003e\u003c\/th\u003e\n\u003cth style=\"width: 68.1637%;\"\u003e\u003cspan\u003eDetails\u003c\/span\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003eItem Type\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eL Bar Mini Prism\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003eSpecification\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eBasic Type\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003ePrism Constant\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eApprox. -25 mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003eEffective Diameter\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eApprox. 25.4 mm \/ 1 in\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003ePrism Coating\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eCopper Coated\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003eMain Material\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eDie-Cast Aluminum\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003eInstallation\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eExtended L-Bar\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003eApplication\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eTunnel, Subway, Mine, Highway, Inspection\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003eUse\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003eMonitoring \u0026amp; Surveying\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"width: 29.0044%;\"\u003e\u003cspan\u003ePackage\u003c\/span\u003e\u003c\/td\u003e\n\u003ctd style=\"width: 68.1637%;\"\u003e\u003cspan\u003e1 × L Bar Mini Prism\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003ch2\u003e\u003cspan\u003eWhy Choose GMP104 Extended L‑Bar Prism?\u003c\/span\u003e\u003c\/h2\u003e\n\u003cp class=\"isSelectedEnd\"\u003e\u003cspan\u003eThe GMP104 combines a \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003edurable metal structure, compact optical prism, and flexible extended L-bar design\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e in one practical surveying accessory. It is designed for professionals who need a stable measurement target in challenging locations.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"isSelectedEnd\"\u003e\u003cspan\u003eIts copper-coated prism supports reliable signal return, while the die-cast aluminum body provides the strength needed for outdoor and long-term monitoring. The extended design also makes installation more flexible in tunnels, subway structures, slopes, and other restricted areas.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eFor surveyors, engineers, and construction teams looking for a reliable \u003c\/span\u003e\u003cstrong\u003e\u003cspan\u003eL-bar prism for tunnel monitoring, subway surveying, and infrastructure deformation measurement\u003c\/span\u003e\u003c\/strong\u003e\u003cspan\u003e, the GMP104 offers a simple and practical solution.\u003c\/span\u003e\u003c\/p\u003e","brand":"SMTOER","offers":[{"title":"Default Title","offer_id":52282793361704,"sku":null,"price":39.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0811\/2134\/5832\/files\/GMP104_Extended_L_Bar_Prism.jpg?v=1787729216","url":"https:\/\/store.smtoer.com\/fr\/products\/gmp104-extended-l-bar-prism-9-inch-coated-optical-survey-prism-for-accurate-subway-tunnel-measurements","provider":"Smtoer","version":"1.0","type":"link"}