Material: made of rubber, with uniform wall thickness, strong tensile strength and good toughness. Color: black grommet caps. 170pcs 7 sizes blanking grommets: 50pcs x 7.14mm, 40pcs x 9.53mm, 30pcs x 12.07mm, 20pcs x 15.88mm, 10pcs x 19.05mm, 10pcs x 22.23mm, 10pcs x 25.40mm. The cable grommets are heat resistant, oil resistant, wear resistant and very practical and convenient to use. There is a thin rubber membrane in the middle so you can pierce it to create your own opening. They are perfect for cars, cylinders, valves, pumps, electrical appliances, chemical pipes, sprays, water pipes, decoration, etc. These rubber washers come in a compartmentalized case, which is very convenient for storage and picking.