bowden rub protector

my top feed tube rubs against the top glass, if you use it. its not expensive to replace it but very inconvenient and easy to forget to check it,this clip on and act and take the wear instead. they clip p on firmly but dont hinder the filament. I use pla as didnt want something too hard and I think a flexible filament would abb drag with the softer surface.I find 3 works well