The Pro Micro is a daughterboard for an Atmel MCU, it comes with standard pitch headers that are quite long, so you need to clip them once you solder it in. And

The Pro Micro is a daughterboard for an Atmel MCU, it comes with standard pitch headers that are quite long, so you need to clip them once you solder it in. And if the solder gobs up, I recommend reflowing it (melting it down) so that you can clip the wires closer