http://www.aubetech.com/products/produi ... noLangue=2
This thing is pretty awesome!! I use it for everything from a block heater to a chicken coup heater light.
It is super ez to program and the AA batts last a year or two.
You can program it to run when the sun goes down or up or when it drops below 32 degrees or at a specific time. Or a mixture of those. Or you can use it as a push button on switch.
I often set it up to kick on the block heater 4 hours before I go to work but it wont kick on in less it is below 32.