6304-2NSENR Nachi Bearing With Snap Ring (C clip) 20mm x 52mm x 15mm Made in Japan 6304-2NSENR Nachi Bearing with a Snap Ring, the 6304-2NSENR inner diameter is 20mm, the 6304-2NSENR outer diameter is 52mm, the 6304-2NSENR width is 15mm.