S 30-35 cm: Inner circumference after retracting 30 cm, total circumference of the collar in the expanded state 35 cm. A dog with a neck of 30 cm and a head at its widest point of 35 cm
M 35-40 cm: Inner circumference after retracting 35 cm, total circumference of the collar in the expanded state 40 cm. A dog with a neck of 35 cm and a head at its widest point of 40 cm
L 40-45 cm: Inner circumference after retracting 40 cm, total circumference of the collar in the expanded state 45 cm. A dog with a neck of 40 cm and a head at its widest point of 45 cm
XL 45-50 cm: Inner circumference after retracting 45 cm, total circumference of the collar in the expanded state 50 cm. A dog with a neck of 45 cm and a head at its widest point of 50 cm