MarkalThermomelt Temperature Indicator Heat Stick, 150 Degrees Fahrenheit, 5" Length

This product works great just as intended. I find it useful when welding thin metal so I don't blow through although I have quite a few co-workers who find them useless in their specialties. I'd recommend buying this if you work with thin metal or need a somewhat accurate indicator of temperature when preheating metal. I give it 5 stars but this is a product that's usefulness is individualized. Always think before you buy but 20 dollars isn't terrible in this line of work either.

The marker will last me a long time as little as I will use it. But had I been in the line of work where I used this daily I would have been upset. The case is just fine, but the crayon is broken into short pieces that will waste most of it.

I uses this to monitor the heat for a silver braze installation on a rifle. The stick worked as advertised, but the stick left a very bad residue behind. After I used aggressive cleaners it came off, but I believe heating it to ~1500-1600 Fahrenheit caused it to turn into a mess.

Works as advertised.

Good stuff, used for years.