The DURAN® Screw Cap GL 45 Thermocouple Holder consists of a holder fitted into a blue DURAN polypropylene GL 45 cap that accepts up to three separate thermocouple wires used in autoclaves or sterilizers. A particular issue when using thermocouples is that their very thin connection wires have a tendency to curl, making it difficult to maintain the tip (where the temperature is measured) in the correct position within the bottle during the entire sterilizing cycle. To overcome this problem, the DURAN® Screw Cap GL 45 Thermocouple Holder has a hollow PTFE tube to keep the wires straight.