5/16" x 7/16" - medium diameter (100FT / ROLL) - Medium Diameter Plastic Mouth Piece/Vinyl Tubing. A plastic mouthpiece that fits on the end of a skinny straight pipe (8mm diameter). Each person should use their own as the tubing prevents burns/blistering to lips, cuts from the pipe and the transmission of certain blood borne pathogens such as HepC and HIV. Should be cut into various lengths as per client personal preference.