This is a bare K-type thermocouple with a standard flat-bladed K-type thermocouple connector on the end. This K-type thermocouple can measure temperatures from -200 to +1250 deg C.
To interface this to a microcontroller, the simplest way is to use an AD595 analog K-type thermocouple interface IC from Analog Devices or the MAX6675 digital K-type thermocouple interface IC with SPI bus.
