These thermocouples seem quite accurate, they agree with two other temperature sensors that I have. Also note that these are twisted at the end, so the temperature measurement is where the twist stops and not at the bead (this is a fundamental property of thermocouples, the temperature is measured at the junction). It is possible to un-twist it and measure at the bead though. I initially only received one 3m thermocouple and four 1m thermocouples, but I was able to solve the problem with customer support. I'd say CG INSTRUMENT is pretty good!