Equip only to a Machine monster. When that attacking monster destroys your opponent's monster by battle: You can activate this effect; it can make a second attack during this Battle Phase. Your other monsters cannot attack the turn you activate this effect.
I wish we get more VRAINS cards in DL. Some of the Cyberse-Type monsters are generic enough to go into DL, and the type even has two Main Deck bosses already, "Dual Assembwurm" and "Degrenade Buster" (which even has protag ace card stats).