Available in either a Valox ™ or Aluminum 9" case, Merit's organic filled (kerosene) liquid in glass thermometers come standard with a 3/4" NPT Brass separable thermowell, 3.5" stem length and are fully adjustable. Low-Lead Brass, 304 SS and 316 SS thermowells are optional. Used primarily in HVAC installations, the Merit TRD9 industrial thermometer meets all industry standards required by mechanical contractors and engineers. Optional 6" stem length with Lead-Free Brass, Brass, 304 SS or 316 SS material is available.