Originally Posted by SeuDog
The "blue" piece is part of the valve housing and not part of the reg tester. The valve housing is held together by screwing it together with the main guide rod. Removing the main guide rod and replacing it with the green reg tester allows you to begin your test. Tapping the end of the valve stem allows you to simulate the hammer striking the valve. The marker is too simple to tech.
That sounds amazingly easy