Markal Thermomelt Temperature Indicator Heat Stick, 300 Degrees Fahrenheit, 5" Length Accurate, fast, low-cost method for measuring surface temperatures Ideal for applications such as annealing, forging, welding, bending, forming Initially the mark appears dull and chalky then quickly melts to a transparent-appearing liquid Accurate to within +/- 1 percent of rated temperature Bigger design makes Thermomelt the industrys longest-lasting heat stick