Johns Manville Micro-Lok® HP plain fiberglass pipe insulation is manufactured using the latest technology and our unique in-line manufacturing process and is available without a vapor retarder. Our in-line manufacturing process results in a uniform fiberglass core that delivers consistent performance during fabrication and installation. Micro-Lok HP delivers thermal performance you can count on, while meeting all industry performance requirements. This assures the building owner, mechanical engineer and contractor that Micro-Lok HP will deliver the performance you've come to expect from JM products throughout the life of the mechanical system.