Specialty: Our products have been strictly tested and controlled, and offer a fast, quiet, wear-resistant, and safe braking effect. Easy and convenient to install, 4 pairs can fully meet your daily needs. It does not damage the wheels and provides a braking capacity that effectively prevents wheel damage due to sand redirection during braking. Specification: Material: copper and metal. Quantity: 10 pairs. Size: 30 x 20 mm. Color: as shown in the picture. Shipping content: 4 pairs of bicycle brake pads.