This is a great scanner. This OBD2 scanner is a replacement for my ancient OBD2 code reader which had finally bit the dust. TOAD Software provides not only the codes, explanation of the codes and visual graphs. It also does your smog test. Prior to buying this I purchased a cheap $40 unit that interfaces with my phone. That company wanted an additional $20 for the software. There were cheap generic software packages for $10-20, but it was impossible to test the software prior to purchasing. TOAD is much better. One off. No future hassle with addons.