Thermalwell for probe type temperature sensor. New design features all brass construction with 1/2" NPT pipe thread. Includes clip to secure sensor wire Overall length is 2", length of probe is 1 1/2". Can be used in a pipe fitting or in 1/2" side port on Rheem and Sunearth HE solar tanks. Fits Steca PT1000, RESOL FKP6 PT1000, and Johnson Controls A421 digital set point probes.