They weigh 19–25 kilograms (42–55 lb) in fit condition and have a height at the withers of 58–61 centimetres (23–24 in) for males, with females slightly smaller. The American Kennel Club standard specifies a very slightly smaller dog. Larger Airedales, up to 55 kilograms (121 lb) can sometimes be found in North America. It is meant to be kept not so long as to appear ragged, and lies straight and close, covering body and legs. The outer coat is hard, wiry and stiff, the undercoat softer. The hardest coats are crinkly or just slightly waved. Curly soft coats are highly undesirable. The patriarch of the breed is considered to be CH Master Briar (1897–1906). Two of his sons, Crompton Marvel and Monarch, also made important contributions to the breed.The first Canadian registrations are recorded in the Stud book of 1888–1889.