Review on Zerostart 3100040 Engine Block Heater: Ford, Lincoln, Mercury. CSA Approved, 120V, 600W by Phillip Ellis

That's cool! Works great on my 2007 Ford Expedition. PLEASE BE VERY CAREFUL WHEN UNPLUGING THE ORIGINAL PLUG! I accidentally hit the block. Luckily the mechanic managed to fish it out. Also, installation will drain all coolant if you have a 5.4 liter Triton engine. There is a drain plug on the bottom of the engine. Drain it first or you'll end up with a face full of coolant.