This is a t-type thermocouple wire in AWG24 with blue high temperature Teflon PFA insulation, which is good up to about 260 degree C Celsius or 500 degree F Fahrenheit. This t-type thermocouple wire can be used to make your own thermocouples for a wide range of applications, or to make your own extension wire. The copper constantan wire is made to standard t-type thermocouple specifications. This is a solid thermocouple wire, which is fairly flexible and useful for t-type extension wires. If you make T-type thermocouple probes they will be very easy to clean, because of the PFA Teflon insulation. Teflon PFA also is resitant to most solvents, such as gasoline, acetone, alcohols, grease and oils, therefore this wire is frequently used in industrial and chemical applications. It is sold in 10 yard spools.