It's practically unused, as I've only plugged it into my smartphone once. The following is a quote: Features - Compact and convenient to carry, it won't get in the way in your bag. - Want to play music data from a MicroSD card... - Transfer SD data from your digital camera to your smartphone... - Want to keep a backup of your contacts... - This product is useful in such situations. Compatible Devices - iPhone - Android - Mac - Windows *Android is only compatible with OTG-enabled devices. *Android/Windows/Mac can be used without an app. *iOS devices require the installation of "iUSB Pro". *Japanese support/Free ☆Notice of change to the iOS app☆ iDiskk Pro has been changed to iUSB Pro. Customers who use iDiskk Pro, please install iUSB Pro. Specifications Data transfer: USB 2.0 (30MB/s) TF/SD card: Up to 128GB Ports/3 types (USB/Lightning/microUSB) USB: For connecting to a computer Lightning: For connecting to iOS devices (iPhone/iPad/iPod) MicroUSB: Android *Please refer to the images for other details. Data Transfer iPhone Backup