This is a standard CX size seal the same as Honda would supply. If you have a CX fiited with the smaller 28mm size then look up 'CX500 smaller seal' on ebay. For hints on fitting this seal look up Happybikes000 on youtube. If you need the fitting service search eBay for 'happybikes seal fitting service' or see item number 134769381087 .This high-quality mechanical seal is designed for HONDA Water Pumps. It is manufactured with precision and made of durable metal material. The seal's mounting style is Press Fit and its diameter measures 28.5mm/31mm. This Premier brand seal comes with a 1-year manufacturer warranty and is perfect for both classic and modern Bikes.