This product is a bulk pack of copper crush washers in various sizes including 1/4, 5/16, 3/8, 7/16, and 5/8 inches. The washers are made of copper with a plain finish and come in Multi-Packs. These DIN125 flat washers are suitable for various industrial and hardware applications, providing a secure seal for fasteners and hardware. Made in China by The Storehouse brand, these washers are ideal for use in a wide range of mechanical and plumbing projects.