optional 5V AC adapter $9.98 110 Volt Input to 5Volt DC 1amp Output designed for our USB Dual Extension Adapter Cable! Works with a lot of USBGear USB Devices including USB Hubs, small Enclosures and Serial boxes. High Output 5Volt DC (+) Center Pin works with all CoolGear Branded 2.5" IDE and 2.5" SATA Enclosures that use 10.00mm long x 3.5mm wide outside (1.3mm inside) Power Connector (as pictured below)