This is a liquid metal thermometer, commonly known as a mercury thermometer. *One item for sale.* I found a few while cleaning, so please let me know if you need one. *Unused.* I've done a simple test with lukewarm water, but if you're concerned, please purchase a digital device. *Liquid metal thermometers that are not mercury are currently available, but I cannot determine if this is one of them.* *I will ship via inexpensive Mercari shipping with free shipping, so if you are concerned about shipping issues, please request cash on delivery.* The thermometer itself has no scratches or stains, but the case (plastic or acrylic?) may have storage scratches, so please refrain from purchasing if you are sensitive to this. Mercury thermometers, which are not often seen these days, are durable, so they are useful as a backup if your digital thermometer malfunctions, or for dealing with and preparing for troubles during disasters.