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.