ProFlex line of universal tubing is a proprietary Fluoroelastomer (FKM) tubing that will Never
harden. ProFlex has been designed and tested to be impervious to gas, glow, diesel, and smoke oil. The thin walls allow maximum flexibility without kinking.
Large Size Tubing has a 5/32″ ID which is designed to fit 3/16″ brass tubing as well as large size fuel fittings. In order to use the large size ProFLex in a tank you must replace the brass tubes and klunk to 3/16″.