I have used several of these portable air compressors and have been a bit disappointed. This one actually worked pretty well and is a Guardian. I was happy with the airflow and pressure build up. I was able to inflate our pickup tire from 10psi to 40psi in pretty much exactly 5 minutes. The noise level was very acceptable. There were only two problems: first, the cable was too short to reach the bar opposite the battery. The battery in our Chevy Avalanche is located on the left side of the engine. The cable could only reach the right rear door and the cable was about 2 feet shorter to reach the tire. The unit came with an extra tube that gave me access to the tire. If the truck was longer (e.g. a long bed truck), the device could not reach the opposite wheel. Another downside to this device is that it potentially draws 25 amps. Most accessory outlets have a 15 or 20A fuse and the compressor will likely blow the fuse every time it is used. This forces the user to connect directly to the battery. The adapter cable that came with the device doesn't hold the plug very well and it broke when I tried to connect the device. Otherwise it was a good little compressor. I think I'll keep it with my emergency tools. If the price was less than $40 I would be a happy backpacker. However, I found it difficult to spend more than $50.