Honeywell High Limit Aquastat Relay W/ 15 F DifferentialHigh Limit Aquastat Relay with 15 F fixed differential. Made in the USA. Product Specifications BRANDHoneywell MAX OPERATING PRESSURE (PSI)225 TEMPERATURE RANGE HIGH LIMIT120-240 SWITCH TYPESPST: High Limit & Circulator APPLICATIONHigh Limit DESCRIPTIONHigh Limit Aquastat Relay LIMITED WARRANTY YEARS1 MANUFACTURER'S PART NUMBERL8148E1299