The St. Bernard is a breed of very large working dog from the Italian and Swiss Alps, originally bred for rescue. The breed has become famous through tales of alpine rescues, as well as for its enormous size.The St. Bernard is a giant dog. The average weight of the breed is between 140 and 264 lb (64–120 kg) or more and the approximate height at the withers is 27½ inches to 35½ inches (70 to 90 cm). The coat can be either smooth or rough, with the smooth coat close and flat. The rough coat is dense but flat, and more profuse around the neck and legs. The coat is typically a red color with white, or sometimes a mahogany brindle with white. Black shading is usually found on the face and ears. The tail is long and heavy, hanging low eyes should have naturally tight lids, with "haws only slightly visible". The eyes are usually brown, but sometimes can be icy blue.
From : http://en.wikipedia.org/wiki/St._Bernard_%28dog%29