Size : Outside diameter
40CM:diameter 40cm fit for pet less than 2.5KG
50CM:diameter 50cm fit for pet less than 5KG
60CM:diameter 60cm fit for pet less than 9KG
70CM:dameter 70cm fit for pet less than 18KG
80CM:diameter 80cm fit for pet less than 25KG
100CM:diameter 100cm fit for less 40kg