Dyson whistle stopper

My Dyson Cinetic Big Ball Animal+ vacuum has developed a high pitched annoying whistle that comes out the end of the wand.

Dyson repair centre has sent out replacement parts but they don't fix the issue. I have figured out the 'whistle' is being produced by the little slots in the top of the extendable shaft where the handle/wand clicks into it.

This small piece fits onto the top of the shaft and covers the holes, stopping the whistle :)