Size 24-25--------Inner length:16.5cm (6.5 inch)
Size 26-27--------Inner length:17.5cm (6.9 inch)
Size 28-29 --------Inner length:18.5cm (7.3 inch)
Size 30-31--------Inner length:19.5cm (7.7 inch)
Size 32-33--------Inner length:20.5cm (8.1 inch)
Size 34-25--------Inner length:21.5cm (8.5 inch)