Thermomelt when temperature measurement is critical. The Markal Thermomelt temperature indicator with superior break-resistance is the industry’s largest, longest-lasting stick, improving efficiency and uptime. New Certified Thermomelt Heat Stiks are specifically analyzed and certified to contain low concentrations of halogens, sulfur and low melting point metals (less than 250 ppm). Ideal for use in nuclear power generation facilities such as shipbuilding, atomic energy or anywhere that nuclear certification is required. 33 Percent bigger and stronger; same proven reliability. Bigger, break-resistant stick cuts down on replacement costs. Improved holder features a durable metal shaft and convenient pocket clip. Gravity advance holder protects stick and prevents it from slipping back inside. Meets ANSI/ASME Code B32.1 and B31.3, AWS D1.1 and ASME Code Sec. I, III and VII, NIST traceable. Typical application includes: ship building, pressure vessels, boiler systems, bridge construction, power piping systems. Made in the USA.