Quality Materials: made of high Quality stainless steel and durable nylon bristles;^Multiple Sizes: set of 10 brushes with various diameters to meet different kinds of cleaning situation;2MM/3MM/4MM/5MM/6MM/8MM/12MM/16MM/20MM/24MM.Total length of all brushes: 8 inches (21 cm)^Easy To Use: it generates foam easily; hard enough to scrub the dirty stuff while gentle enough to avoid scratching;^Multipurpose: for cleaning reusable straws, funnel necks, tube or cylinder and other hard to access corners like tube/bottle with narrow necks;