4 colors, 5 sizes, comprehensive coverage for birds of all sizes.XS: The length of the headband is 5.5cm, the height from the head to the body is 5cm, and it is suitable for a bust of 42cm or less. The total length of the traction rope is 120cm. It issuitable for the size of the parrot about 75-100g. S: The length of the pullover is 6.5cm, and the height from the head to the body is 6.8cm, which is suitable for a bust of 47cm or less. The total length of the traction rope is 120cm. It is suitablefor a parrot body size of about 110-190g. M: The length of the pullover is 7.5cm, the height from the head to the body is 8cm, and it is suitable for a bust of 51cm or less. The total length of the traction rope is 130cm. It is suitable for a parrotbody size of about 190-420g. L: The length of the headband is 9cm, the height from the head to the body is 10cm, and it is suitable for a bust of 62cm or less. The total length of the traction rope is 130cm. It is suitable for a parrot body size ofabout 425-600g. XL: The length of the headband is 10.5cm, the height from the head to the body is 12.5cm, and it is suitable for a bust of 76cm or less. The total length of the traction rope is 130cm. It is suitable for a parrot body size of about600-1000g.There will be slight errors in manual measurement. We have tried our best. The recommended parrot body size is only for the reference of small owners, please understand