Honeywell Aquastat Controller, High or Low Limit, Immersion Device for Limiting or Regulating Temperature of Liquids, 3/8″ x 2 7/8″ Copper Bulb, SPST Contacts Break on Temperature Rise, Horizontal or Vertical Mounting, 100-240 Degree Operating Temperature Range, 3″ Capillary Length, 5-30 Degree Differential Temperature, Factory Set Stop at 240 Degrees, Includes Heat Conductive Compound