100 spacers that are big Dog #BD21451P . They measure 3/8" x 3/4" x 5/16". They look to be polished and not Chrome plated but I'm not sure. I got a huge box of these when Big Dog went out of business and if you purchase one listing you will get 100 spacers. The inside diameter of the hole is 3/8 in. The overall diameter of the spacer is 3/4 in and the thickness is approximately 5/16 in.