13.5cm inside size 21

Size 22 has an insole length of 14cm

Size 23 has an insole length of 14.5 cm

15cm inside size 24

Size 25 has an insole length of 15.5 cm

Size 26 has an insole length of 16cm

Size 27 has an insole length of 16.5 cm

17cm inside size 28

Size 29 has an insole length of 17.5 cm

Size 30 has an insole length of 18cm

21-25 yards, 5 pairs in one hand

26-30 yards, 5 pairs in one hand