Our premium brushes contain no metal parts to ensure the safest cleaning experience and to avoid marring delicate paint or interior finishes and intricate wheel designs.One hole design on each brush let you put a string or something on the handle where the hole is to help you hang onto these longerVARIOUS SIZE - 5 different brush sizes, you can choose any one to suit your needs, enough length for easily exploring and reaching into the lug nuts, narrow or tight space.NO METAL PARTS - Made of boar hair mixed with synthetic fiber,the right combination of strength and flexibility.No chance of marring or scratching your delicate wheels.GENTLE SOFT - Great for using on soft Nappa leather seats or trim such as exterior emblems.