50 pieces durable shiny Collet bits # 481 for 3/32”(2.38mm) diameter bits. Collets are all 3/4" (19.05mm) long. 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 for Dremel 225 and compatible Flex-Shaft attachment. | US-BASED CUSTOMER SERVICE: Available by chat, email, phone, or visit us at our customer service center in La Crosse, WI.