Bio Overcheck Straps:

The overcheck is used on horses that will not hold its head up.This is used on most show horses.  The strap attaches to the overcheck bit (sold on the driving bit page) on one end, crosses between their eyes, goes between the ears thru a slot made in the bridle crown and attaches to the rein chains. The rein chains are left on the bridle for looks and just snap to the bridle ring by the bit.