The ECESATA254F Flush Mount 2-Port e SATA Express Card Adapter uses a unique slim 54mm form factor design that allows it to sit fully in a standard laptop Express Card/54 slot without sticking out. When installed, the ports sit flush with the sides of the laptop, creating a seamless add-on that can be left installed at all times, without fear that it or the card slot will be damaged due to snagging or impact. The e SATA Express Card adapter features 2 independent e SATA ports, & is compatible with the latest high capacity SATA drives (SATA I, SATA II) with support for data transfer speeds up to 3 Gbps. With support for Port Multiplier technology & hot-swap installation, the e SATA Express Card allows compatible multi-drive enclosures to be connected over a single e SATA cable, & devices can be connected & disconnected without having to reboot the system.