Whether you have a flat tire or are getting ready to paint a room with a paint sprayer, you need an air compressor to operate your tools. Portable air compressors can be anything from small, 12-volt battery-operated systems to those with large 5.5 horsepower motors and up. Portable air compressors are electric or gas-powered and there are pros and cons to both types. Portable gas air compressors work best in outdoor settings, as they are louder and have exhaust that can be dangerous in indoor settings, but they are heavy duty and reliable. You can also use them in remote settings where electricity is not available. Portable electric air compressors, on the other hand, either use a battery or need an outlet to operate, but they are easy to use and store since you do not have to worry about storing gas as well. These units work great in indoor settings and are quieter than gas machines, but they are not as powerful and may not be able to perform all of the functions that you need. Portable air compressors are great to have on-hand for a variety of applications, and with the large inventory on eBay, you can find just the right compressor for your tools.