size:21 yards are 13CM long, 22 yards are 13.5CM long, 23 yards are 14CM long, 24 yards are 14.5CM long, 21-25 yards are 5 pairs per hand, 25 yards are 15CM long, 26 yards are 16CM long, 27 yards are 16.5CM long, 28 yards are 17CM long, 29 yards are 17.5CM long, 26-30 yards are 5 pairs per hand, 30 yards are 18CM long
