The 648827 from DenLors Tools makes adjusting valves easier, designed for engines with a 10mm jam nut and slotted valve adjusting stud. Unique all-in-one design positively tightens jam nut while preventing stud movement. It has a 7-1/2" handle that provides the necessary torque for loosening jam nuts on the adjusters (very similar to the Snap On design at a fraction of the price). The view window shows screwdriver blade position for easier engagement, see the related DenLors "How To"
Honda Valve Adjustment article.