NECK SIZES: (not collar length)
Widths in ( )
Size 2 (2cm/3/4") 22-26cm/8.5"-10"
Size 3 (2.5cm/1") 30-34cm/12"-13.5"
Size 4 (2.5cm/1") 34-40cm/13.5"-16"
Size 5 (2.5cm/1") 40-48cm/16"-19"
Size 6 (3cm/1.25") 50-58cm/19.5"-23"
Size 7 (4cm/1.5") 55-65cm/21.5"-25.5"