Get a super adorable costume for your dog,Be Suitable for Christmas day,Halloween party,and etc.Match with a Santa caps. This costume is made of high quality materials. It's soft and comfortable for cats and small to medium dogs. It's a best Christmas gift for dogs or cats. You would get more happiness when the lovely pets get the Holiday costume. Size:(back length * bust * collar, cm) XS: 20*30*21 S: 25*35*24 M: 30*40*27 L: 35*45*30 XL: 40*50*33 How to choose the size 1, It is recommended that you measure your dog's chest circumference and the standing height and neck circumference. chest circumference is the perimeter of the widest of dogs chest.the standing height is from your dog foot to your dog neck. 2, The pet costumes is a standing clothingplease mainly consider the chest circumference and neck circumference and standing height. and back length isthe auxiliary factor. 3, Your pet usually wears size S doesn't mean all size S will fit him/her.