NOS New/Unused Vintage Miyata Unicycle Bearings, made by IKS in Japan.  80s stock.  6203Z hub / fork unicycle bearings.  Metal seals.  40mm OD, 17mm ID, 12mm thickness.  NOS, smooth and perfect.  Correct bearings for your Miyata unicycle.  Listing is for 2 bearings.  Buyer to pay $6.00 USPS Ground Advantage shipping with tracking.  Thanks for looking!