These spirit filled, non-mercury thermometers are housed in unbreakable plastic bottles filled with a non-toxic insulating liquid, used to ensure accurate temperature readings without being affected by the opening and closing of a chamber door.

Thermometers are fluoropolymer coated for additional protection. All thermometers have thoroughly annealed glass and engraved stems for lasting accuracy in 0.1, 0.5 and 1 °C divisions. Magnets are included to attach thermometers to a steel door or wall.