Size: 24-25 [inner length 16.5cm] children Size: 26-27 [inner length 17.5cm] children Size: 28-29 [inner length 18.5cm] children Size: 30-31 [inner length 19.5cm] middle child Size: 32-33 [inner length 20.5cm] middle child Size: 34-35 [inner length 21.5cm] middle child Size: 36-37 [inner length 22.5cm] adult Size: 38-39 [inner length 23.5cm] adult Size: 40-41 [inner length 24.5cm] adult Size: 42-43 [inner length 25.5cm] adult Size: 44-45 [inner length 26.5cm] adult