Lenght of cylinder 12 inch (30 cm), three inches (7.5 cm) longer then all our other cockcylinders!Available in the following sizes (inner diameters):• 3.50 inch (8.9 cm)• 4.00 inch (10.2 cm)• 4.50 inch (11.4 cm)• 5.00 inch (12.7 cm)• 5.50 inch (14.0 cm)