All brands of hard drives areÂ standarized and very generic.Â  CAVSÂ DVD Karaoke players are compatible to most, if not all,of theÂ brands. However theÂ USB external cases that encloses the hard drives are not standarized in any sense.Â Â There are many different manufacturers and it is hit-and-missÂ dealing with them forÂ the compatibilityÂ to CAVS DVD Karaoke players. We are currently using the following hard drives: All hard drives enclosed inÂ iMicro USB External cases Seagate Free Agent Iomega Silver Series We recommend avoiding the hard drives ofÂ following specifications: Over 1 TB (we have successfully tested only up to 1 TB) Additional functions (such as 1-touch Backup, Power saver) No self power supply (for 60GB or more) Note: Compatible USB external hard drives (250GB, 500GB, 750GB, 1TB) can also be purchased at CAVS USA Inc.Â  Please contactÂ sales@cavsusa.net.Â