DURABLE – These industrial grade Phenolic Caps are made to withstand strong chemicals and solvents as well as extreme temperatures (-150°F to 250°F) QUALITY DESIGN – The continuous threading on the cap in addition to the Poly Cone liner insert offers a Superior Seal. Providing a seal at the top rim and another seal at the inner diameter of the container’s mouth opening, these caps will prevent any unnecessary leaks, spills and evaporation. VERSATILE SEAL – Use these caps to seal in chemicals, solvents, oils, essential oils, soaps, cleaners, fragrance oils, and other liquids in our glass bottles