We offer four different sizes:Small: 24in / 60cm diameter for dogs up to 25lbs / 11kgMedium:  28in / 70cm diameter for dogs up to 45lbs / 20kgLarge: 32in / 80cm diameter for dogs up to 60lbs / 27kgExtra-Large: 40in / 100cm diameter for dogs up to 100lbs / 45kg