Item DescriptionSeal your liquid bottles tightly with Labelmaster's Phenolic Caps With Teflon® Liners. These have the excellent chemical resistance of Teflon with the compressibility and sealing properties of polyethylene foam. The plastic caps fit a 500cc, 1-, 2.5- or 4-liter glass bottle with a mouth size of 38/439. Typical uses include analytical lab samples, high purity chemicals, strong acids solvents, environmental samples, pharmaceuticals and diagnostic reagents.