Frio-Temp verification thermometers for sample temperature measurement within incubator without introducing contamination. These thermometers are filled with environmentally safe non-toxic, non-hazardous, biodegradable Enviro-Safe liquid, EnviroKleen certified by ChemTel, an independent laboratory comparable in accuracy to mercury filled thermometers, but are 100 percent environmentally safe. Contain multi-language instructions (English, French, German, Italian, Portuguese and Spanish). 0.5 Degree C accuracy. 0.5 Degree C division. 135mm Length.