#26 Inner Dimensions: 6.3 inches (16.0 cm), 27 #Inner Dimensions: 6.5 inches (16.5 cm), 28 #Inner Dimensions: 6.7 inches (17.0 cm), 29 # Inner Dimensions: 7.1 inches (18.0 cm), 30 # Inner Dimensions: 7.9 inches (18.5 cm), 336 inches (2 inches (2 cm). 2.0cm + 0.3cm error is allowed.