Need to know if you have the S flex shaft or the R flex shaft to begin with. They list multiple options for trimming. We list the mid range trimming solution for the flexes between the softest option and the stiffest option that they list on their website. Our trim code for the R flex or the S flex .370 parallel tip Tour 90 shaft is IR3. This code lists 0 tip trim for a #1 iron, 1/2″ tip trim for a #2 iron, 1″ for a #3 iron and continuing in 1/2″ increments until you get to 4″, which would be the max trim for the 9, PW. After tip trimming and installation, you would trim to your playing length from the butt end. If you want to go to the stiffest trim option they list for the Tour 90 flexes, it would be our code IR39, which calls for 2.5″ tip trim on the #3 iron, with 1/2″ increments up to 5.5″ on the #9 and PW. It is a little confusing on their website for sure.