Sabrent USB-CBBH USB 2.0 Flexible Bus-Powered 4-Ports Mini Hub Adds 4 USB ports, compatible with 1.1 Power Bus power: 500mA per port; No External Power Source Needed Compliant with Universal Serial Bus 1.1 ; Access up to 4 USB devices simultaneously Plug & Play Installation Specifications : 4 USB Ports; Supports All USB 1.1 Devices Individual Port Over-Current Protection, ergonomic design. Easily portable. Requirements : IBM Compatible Pentium-233 MHz or faster and MAC PCs; 64 MB RAM or more