Product review (5 stars): OEM Knob - watch for the snap washer
This knob is the OEM knob for the unit.  Pulling out the snap washer can be tricky and putting back in can be trickier.  Use a butter knife or something to nudge out then pull it with a small pair of needlenose pliers.  To put it back, have the snap washer partially in when you put the knob back on.  Beware- the snap washer has a horrible tendency to pop off and most laundry rooms are a little clutter to lose a piece of flimsy plastic which is essential for the knob.

The nubs on my old knob wore off and this was an easy fix to make life so much easier.  Old knob shown - problem completely fixed.