Tank Buster is a gear perk that fully restocks your gadgets when you destroy a tank. Tanks are among the toughest FND threats, and this refills your grenades and other throwables for the next fight.
Destroy a tank and your gadgets refill to full. You can spend them freely during the tank fight knowing you will get them back.
Wear the Soviet Watch in the hands 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.
Launchers and explosive gadgets that kill tanks quickly. Tank Commander and Safety First complete a vehicle-themed set.