And when they attach, they basically contract. And when they contract, they bring these actin, these thin filaments, close to one another and we have overlap taking place, but the entire length of our thick filament does not actually change. So this is when our sarcomir is basically relaxed. But when we have contraction, we basically move these z lines closer to one another. So when a contraction takes place, these z lines come closer to one another, so that the distance between the z line and this z line actually decreases. And what that means is this A band will also decrease.