Aquastat Controller, Circulator Application, 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 Adjustable Differential Temperature, Factory Set Stop at 240 Degree