The red LABSOLUTE® screw caps and pouring rings made of PBT are the perfect complement to the LABSOLUTE® clear and amber laboratory glass bottles with GL45 thread. Both the caps, delivered with a PTFE-coated silicone seal, as well as the pouring rings are temperature-resistant up to 200°C. Therefore it is possible to sterilize them with hot air at 180 °C. Evaporation of highly volatile substances is avoided by the additional seal.