Review on iSaddle Universal AC to DC Car Cigarette Lighter Socket Adapter Converter - Vehicle Power Inverters, Amplifiers, and Car Refrigerators (US Plug, Output: DC 12V 500mA) 110V AC to 12V DC by Leroy Estell

UPDATE: Okay, stopped working the second time I used it. Like many other reviewers, it doesn't output 12 volts - not enough to run my 12 volt compressor. Thanks to the person who came up with this adapter. I have a tiny travel air compressor (usually only used to inflate car tires). However, I like to use it in my garage to inflate my tractor tires. I always had to pull the vehicle right next to the tractor to hitch it to the vehicle and inflate the tires. NO LONGER! Now I can just stick it in the wall and inflate it without any extra steps. Small and cheap way to solve my problem and save time :)