Data key is a very useful instrument, that allows the user to store data sampled by MyChron4 and to download them on a PC for analysis through the powerful Race Studio 2 software. With its 32MB memory it can record numerous sessions data. Thanks to Data key there is no more need to wait for data download: just remove Data key from MyChron4 and plug it in PC USB port like a normal compact flash. No session (race or test) stop is needed if another Data key is immediately connected to MyChron4. Features Dimensions: 86x25x13.5 mm Weight: 30 g