PTFE Washer that will not disintegrate like the Standard or Replacements made of the same material.
Also adds the benefit of more power.
Picture shows what happens to the Standard or similar Washers.
I have added the option of adding the MS 40 Silicon Oil for £4.25 as this is important to lube the washer edge with this.
Mushroom fitting just presses in when you have cleared out the old crumbs.