(S) outer diameter/length: 27*27*28cm; door hole: 17*17cm; weight: 0.25KG, suitable for dogs and cats about 3 KG.
(M) outside diameter/length: 32*32*33cm, door hole: 20*20cm weight: 0.31kg, suitable for cats and dogs about 5 KG.
(L) outer diameter/length: 39*39*40cm, door hole: 25*25cm weight: 0.45kg, suitable for cats and dogs of about 10kg.
(XL) outer diameter/length: 48*48*50cm, door hole: 29*25cm weight: 0.68kg, suitable for dogs and cats about 20kg.
the manual measurement has slight error (1-2)cm, in view of some dear friends bought the product feel too small is not suitable for the situation, strongly recommend the original size on the basis of the recommendation to buy a larger!!!