What replacement plunger do I need for a YHS (Standard) series Boshart yard hydrant?

What replacement plunger do I need for a YHS (Standard) series Boshart yard hydrant?

The YHS Series repair kit has two plungers with slightly different diameters due to a slight change to the valve bodies back in 2011.

When the plunger is removed for replacement, simply select, and install the plunger that matches the one you removed. They are easily identified older models prior to early 2011 have a brass threaded core that does not extend to the top edge of the rubber. On the newer models manufactured in late 2011 on have a brass threaded core which is flush with the top edge of the rubber.