Well, the title says it all. Portable Battery Jumpers. Mine saved my back-side today. When going to leave work, went to crank the motor, nothing. checked everything, turns out it was the battery (still the original from 2006). There was no one else in the lot, and my cell phone had already died. Luckily for having the "Beast" (got it from Sportsmansguide . com a few years ago) I was able to make it home, and not have to walk a few miles to the nearest building. Who else carries one in their Rav4? Mine has a built in compressor, USB, 120V converter, work/area light, and then the jumper itself. I charge it once every 3 months just to make sure its always charged up.