At three years old males are no longer considered calves; they are known as "novillos" and are ready for bullfighting, although "novilladas" are for training bullfighters, or "novilleros". The best bulls are kept for "corridas de toros" with full matadors. Under Spanish law they must be at least four years old and reach the weight of 460 kg to fight in a first-rank bullring, 435 kg for a second-rank one, and 410 kg for third-rank rings. They must also have fully functional vision and even horns (which have not been tampered with) and be in generally good condition.