This is a compact USB OTG (On-the-Go) adapter that allows you to connect peripheral devices to a USB OTG-compatible device. On one end, there is a micro-B plug on the other end can be inserted into a regular type A male USB connector.

This adapter is so compact and convenient to use. It is the kind that you can plug-and-forget. The dimension is 16 x 11 x 2 mm.

Many mobile phones, tablets and even boards such as Arduino Due, Raspberry Pi Zero and Odroid supports USB OTG so you can connect a keyboard, mouse, flash drive or any other supported USB devices.