The Yak is highly valued and its long, hard outer hair is made into ropes and harnesses, waterproof tents, durable mats and sacks. In former times – long before snow goggles appeared – it was even used for protection against snow-blindness. The commonest eye preservers consist of a gauze netting of closely plaited black yak hair. The soft, down-like inner hair of the yak is woven mainly into soft blankets. Some clothing is made from the hair of the young, two and a half to three year old yak. Yak-hair items are highly regarded by the sherpas as items of trade as well as for use at home and as part of the dowry.