These are used to protect some particular parts of the vehicle from dust. Rubber Bellows and Rubber Gaiters are also used to protect from dust, debris, weather conditions, etc. thus increasing the life of those parts & vehicle.
These are rubber rings which are used to protect some delicate type of things like wires from the sharp edges of the metal.
Rubber grommets are also important parts in automotive applications. They are used to protect lines, wires and cables from chafing or grazing on rough surfaces. They can