IT’S AN AWESOME TOOL. IT’S AS EASY AS CONNECTING IT TO THE MYCHRON 4 AND JUST DRIVING AROUND. THEN YOU DOWNLOAD IT (NEED THE KEY) AND CAN REVIEW ALL SORTS OF DATA (YOUR DRIVING LINE, LATERAL ACCELERATION, ETC.)
A single 9V will last for a day or two of driving. So $2 a day to use it. There are hooks on the extension box that comes with it to put in a larger battery, but so far I’ve not found replacing the battery to be that big of a deal.