By making a substitution of an IN LINE sleeve for a standard compression sleeve it is now possible to have an economical multi-purpose fitting suitable for use with plastic or metal tubing. The tapered nose of the sleeve gives a wedging action when tightened that provides a vacuum tight seal that doesn’t necessarily distort the tubing wall. The sleeve remains “In Line” with the tubing hole in the nut and body during warehousing eliminating the necessity of taking the fitting apart when assembling to the tube. Simply slip the tubing into the fitting and tighten the nut. Especially suitable for plastic tubing, however, when then or soft wall types are used an internal reinforcement may be necessary.