Honeywell Circulator Aquastat ControllerCirculator Aquastat Controller with 100 F to 240 F operating temperature, 5 F fixed Differential. Product Specifications BRANDHoneywell LENGTH INCHES2-7/8 DIAMETER INCHES3/8 CAPILLARY LENGTH INCHES1-1/2 WELL SPUD SIZE INCHES1/2 TEMPERATURE CONTROL RANGE °F100 to 240 SWITCH TYPESPST, contacts make on temperature rise APPLICATIONCirculator DESCRIPTIONCirculator Aquastat Controller LIMITED WARRANTY YEARS1 MANUFACTURER'S PART NUMBERL4006B1007