The Big Bore Adjustable Blowpipe is turned from solid delrin for durable construction and adjusts to various lengths. The blowpipe has a 3/8″ bore together with sturdy, replaceable built in valve. Oval mouthpiece is also built in. Latex Sleeve included. The length of a blowpipe is taken from the mount to the tip. The length does not include the tenon(the hemped part) Sizes are as follows: Small: 7″ to 8 1/2″ (178mm to 216mm) Medium: 8 1/2″ to 11″ (216mm to 279mm) Long: 10″ to 13″ (254mm to 330mm)