Super Precision Ball Bearing 7904CYU/GLP4 Nachi Angular Ball Bearing Phenolic cage, Flush ground single unit 15 degrees Contact Angle Abec-7 20mm x 37mm x 9mm Made in Japan 7904CYU/GLP4 Nachi super precision Angular Ball Bearing with 15 degrees contact angle and Phenolic cage, bearing is ABEC-7 (P4) quality and made in Japan, inner diameter is 20mm, outer diameter is 37mm and width is 9mm.