This is a K-type thermocouple with a stainless steep probe on one end and a standard flat-bladed thermocouple connector on the other. K-Type thermocouples can measure temperatures greater than 1000 degrees Celsius. However in this case, the stainless steel probe is only rated to 600 deg C. Hence the range of this probe is rated at -200 to +600 deg C. Its fine for standard oven types of applications, but for hotter temps like blast furnaces, its probably to use the thermocouple without the stainless probe.
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.
The stainless steel probe dimensions are: 3mm diameter x 76mm probe length. The full length of the probe is 120mm including the handle.