Ship your liquids with confidence when you use Labelmaster's Polyseal® Phenolic Caps with Polyethylene Disk Liners. Designed to fit a wide range of glass, poly or French square bottles with mouth sizes from 43/400 to 58/400, these black caps are stress crack-resistant and offer superior torque retention and excellent sealing characteristics. You can rest assured knowing that your liquid shipments will arrive intact as we put our bottle caps through extensive testing to ensure tight seals and unrivaled durability.