Manual thermometers with riser displays such as this one have two advantages. They work without batteries and can, therefore, be used at any time, and their glass body enables hygienic cleaning and re-use. The riser in this model manufactured by German medical technology specialists, Geratherm® contains a gallium-indium-tin alloy known as Galistan, a trademark registered by Geratherm Medical AG. Galistan is non-toxic, but extremely accurate, with a maximum measurement tolerance of only 0.15°C.