U.S. Sensor/Littelfuse has two styles of UL-recognized thermistors, a Ring Lug probe assembly (USUR Series), as well as a DO-35 style glass encapsulated device (USUG Series). The Ring Lug "USUR" series has a 125°C maximum operating temperature with 28 AWG lead wire and a #6 mounting hole stud size. The DO-35 "USUG" series has a maximum operating temperature of 150°C and is hermetically sealed in a glass package resulting in excellent long term reliability and stability. These products are offered in a wide variety of resistance values and resistance tolerances.