CBR400 NC29 Gullarm and CBR400 NC23 Tri arm GF Racing OEM spec. main cam cover seal. You will love the quality of these - I've had them remade to world class OEM spec. As per OEM: 12391-MV4-000. GSP is fine.
This product would be best fit for Honda CBR400 bikes with NC29 and NC23 cylinder heads that require a cam cover fitting seal.
