4" Temperature Sensor DS18B20.  The DS18B20 sensor is epoxy potted in a 4" 316 stainless protection tube. The overall length including the cable is 8' from the tip of the tube to the end of the cable.  The high quality cable has 22 guage conductors, is foil shielded and has a drain wire.  No other electronics such as a filter circuit or drop resistor are soldered in, allowing for more versatility in applications.