Harp seals can grow up to 2 meters in length and 160 kg in weight, with females being slightly smaller in size than males. Males are silver gray with black heads and black "horseshoe" or "harp-shaped" markings on their backs. Females are paler color and have markings that are less distinct. Often the color of females is broken up into spots. Usually, the coloration of the seals changes with age. In April and May, harp seals shed their coats and grow new ones.