I'll second that the wifi ones are nice, but don't always work right. That's what I currently have that I use for checking codes on other people's cars, and it's great for running simple scan tools and resetting codes, but it doesn't seem to cooperate with more advanced software, such as Forscan. It errors out every time I try to write to the car. I gave up and ordered a OBD to USB cable to have another go at it.