This is a set of 2 adapters from USB-C to Micro-USB.
You will need such an adapter for example to charge a new smart phone with USB-C connector, but you only have the older standard Micro-USB cable available.
All pins of the Micro-USB side are connected to the corresponding pins on the USB-C side. This enables this adapter to be used for charging / power supply and data transfer as well.
The adapter is 25mm long and easily fits in your wallet to be always available in case you need it.