Data key 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 Data key there is no more need to wait for data download: just remove Data key from MyChron4 660 and plug it in PC USB port like a normal compact flash. Features Dimensions: 86x25x13.5 mm Weight: 30 g