The ECUSB3S1 Flush Mount 1-Port USB (Universal Serial Bus) 3.0 Express Card Adapter uses a unique form factor design that allows it to sit fully in a standard 34mm laptop Express Card slot without sticking out; the port sits flush with the sides of the laptop, creating a seamless add-on that can be left installed, even while on the move, without fear that it will get snagged or hit against which could cause damage to the card or slot. The USB (Universal Serial Bus) 3.0 Express Card supports data transfer rates up to 5 Gbps, & is still backward compatible with USB (Universal Serial Bus) 2.0 at up to 480 Mbps, or USB (Universal Serial Bus) 1.1/1.0 at up to 12/1.5 Mbps respectively.