RR style RTD probe allows for the sensor to be installed in a thermowell while mounting the head remotely.  This protects the instrument connection from excessive heat or vibration while added PVC or FEP to armor protects from chemical or moisture.   This probe is commonly used in the Oil and gas industry.  Available in 316 stainless steel 400°F (204°C), .125", .188" and .250" diameters.