50 piece set of durable, shiny Collet bits # 480 for 1/8”(3.175mm) diameter bits. Collets are all 3/4" (19.05mm) long. Will Compatible for Dremel except discontinued Models 1, 2, and Series 1 or earlier of discontinued Models 260, 270 and 280. It also fit many other compatible rotary tools. Collets are Compatible for Dremel 225 and compatible Flex-Shaft attachment. Durable and long-lasting for extended use.