Quick Fingers, Quick Feet is a gear perk that lets you move faster while reloading. It keeps you mobile during the slowest part of a gunfight, so you can reload on the way to cover instead of standing still.
Your move speed goes up while a reload is in progress. You can reposition after emptying a magazine without being as easy a target.
Wear the Munitions Boots in the feet slot. Gear perks are fixed to the piece of clothing that carries them, so you get this one by wearing that piece, not by unlocking it in a menu.
Pair it with the other Munitions pieces for ammo reserve perks, or with heavy weapons that take a while to reload.