DataKey is a very useful instrument, that allows the user to immediately record data sampled by MyChron4 660 during test session and runs as well as their download on a PC for analysis through the powerful QMAn software. With its 32MB memory it can record numerous sessions data. Thanks to DataKey there is no more need to wait for data download: just remove DataKey from MyChron4 660 and plug it in PC USB port like a normal compact flash. Features Dimensions: 86x25x13.5 mm Weight: 30 g