Pug is a breed of toy dog, believed to have originated in China, from which it may have been imported into England in the 16th century. The modern pug is descended from dogs subsequently developed by English breeders. The dog has a short, compact body; a large, round, and massive head with profuse wrinkles; a short, square, and blunt muzzle; large, bold, dark eyes; straight legs; and a tightly curled tail. The coat is close-haired, soft, and glossy. The color of the pug is silver or apricot-fawn with a black mask, in either case with a black trace from the middle of the skull to the tail; or it is solid black. The animal is about 30 cm (about 12 in) high at the shoulder and weighs about 6 to 8 kg (14 to 18 lb). Because of its alertness, tractability, and friendliness, the pug is a popular pet.