The 90 Degree Up & Down Angled Mini USB 5pin Type B male to USB Female OTG Adapter converts your MINI USB On-The-Go capable tablet computer or Smartphone into a USB OTG host by adding a USB port to your mobile digital device, which increases its functionality and enables you to use a USB peripheral such as a thumb drive, or a USB mouse or keyboard, etc. Backed by our lifetime warranty, this MINI USB OTG Adapter is constructed for maximum durability, to ensure dependable, long-lasting connections. it also works with an external hard disk, But It needs an external power source for the hard disk, It should also work with the non-power card reader.