This K-type thermocouple is great for high-temperature measurement. We love the the integrated winding wand for keeping the wire nice and organized.
While the tip of this thermocouple can measure the K-type temperature range of -270 to +1372 C (-454 to +2501 F), there are things to keep in mind. In a non-oxidizing atmosphere the metal of the wires will operate up to 1260 C; at higher temperatures the atmosphere will have to be composed of inert gas. The PTFE jacket material on this wire is good up to 260 C, so you'll be fine measuring a flame temperature, but don't route the wire through an area that is above 260 C.