connector 1 : Micro USB female
connector 2 : USB Type C (USB-C) male
The connector allows you to use your existing power supply with micro USB plug from the Raspberry Pi 3B and fits perfectly to the new Raspberry Pi 4B.
Bear in mind that the connector won’t increase the capacity of your existing power supply. In case of doubt, please check the capacity of your power supply. A capacity of 2.5A should be enough for normal usage of your Pi. An adapter of 3A is recommended for intensive CPU usage and/or if USB devices are connected.