Dew Controllers allow you to manage the level of heat being distributed to your dew heating strip or your heated dew shield. This allows you to dial in the heat output on your dew heating strips to best prevent dew accumulation on your telescope.
The Thousand Oaks DDHC Dew Controller offers four dew heating strip outputs so you can individually control four dew heating strips at once. The unique part of the Thousand Oaks DDHC is that each dew heating strip connects to its own temperature knob. This means that you can control the individual temperatures of four different strips at any given time.
Other dew controllers such as the AstroZap Dew Controller offer multiple dew heating strip connections as well, though it does not allow you to individually control each of the heat strips attached to your telescope. This controller works very well but if you truly want to geek out and experiment with optimal dew heater temperature the Thousand Oaks DDHC is the way to go!