Gemini Tapered Edge Strip (TES) is produced with a tapered closed-cell polyisocyanurate (polyiso) foam core integrally bonded to non-asphaltic, fiber-reinforced organic felt or inorganic coated-glass facers. The dimensionally stable Gemini TES provides a Zero Edge polyiso tapered insulation transition of either 1.0" per ft. or 1.5" per ft.