Computer Connection Type of connection needed to link the device to your computer. It is important to verify if your computer support those connections. For example, if your computer only accepts USB 1.1 and your card reader is USB 2.0 compatible, the speed at which the information is transferred might not be maximal. Transfer Speed Transfer speed from the card to your computer expressed in megabytes per seconds. Someone who has large data to transfer might want to choose a faster device. Write Support The device also has writing capabilities from your computer to the card. It is useful when someone want to transfer somebody else's pictures to his/her card. Additional Features Reads most types of memory cards Uses USB 2.0 for fast downloads at up to 480Mbps Ability to use up to four different types of cards at once and you can copy files between cards and your computer Works as a USB hub to connect up to 3 other USB devices to your computer. Purchase the optional AC adapter and it upgrades to a powered USB hub for best performance with your high power draining peripherals.