Pattern cam end plugs for the Z1 series engines. This is the same as OEM part No 92066-017 and is supplied in a pack of 4.If not installed correctly they can leak.The round section that fits in the 'D' shaped cutout in the cylinder heads should be thoroughly degreased using brake cleaner or similar volitile degreaser as should the cutout. This mating surface should be smeared with . The top surface should be coated with whatever gasket jointing compound you use; we use Wellseal which is excellent.Suitable for Z1, Z1A, Z1B, Z900 A4, Z1000 A1, Z1000 A2, Z1000 D1 and Z1R