About the Full Tilt (now K2) Ski Boot FTE Tongue Flex 6
Full Tilt replacement tongue with a flex of 6, equivalent to flex rating of 90. This tongue is compatible with any Full Tilt boot with an Evolution shell.
To identify the shell of your Full Tilt boot all you need to do is count the number of screws on the bottom of your boot. Full Tilt boots with an Evolution shell have 8 screws holding the sole in.