HEAD 16X FREEFLEX RACE BINDING. The 2012 HEAD 16X Free flex Race Binding is a true race binding that is tried and tested. This is the same COMP Binding as other Head, Tyrolia, and Fischer X Series Comp Bindings. This is for the racer looking for very consistent retention and precise boot to binding connection. This is the lightest version of the X or Comp Bindings with a din of 7-16.