Tube fitting users have long recognized that proper tube and tube fitting system function requires good tubing preparation followed by the use of correct installation procedures. Improper ferrule set in any flareless tube and fitting system may be the result of burrs created during the tube cutting process, improper tube insertion into the fitting, or inadequate tightening of the fitting nut. In order to maximize tube and fitting system performance and safety, HOKE offers several tool options combined with detailed installer training. The Gyrolok® Marking Tool provides the installer with an economical means of ensuring both proper tubing insertion into the fitting and adequate nut tightening.