Two sizes available
2001-2005 Large (1 required)
2001-2020 Small (2 required)
OEM Yamaha 'O' rings used to seal the coolant gallery water pipe.
On 2001-2005 models three 'O'rings are used, one large to seal joint to Thermostat and two small to seal pipe to cylinder head. 2006-2020 just require two small'o' rings to join 'H' pipe to cylinder head.
Always use new O rings and make sure the mating surfaces are scrupeously clean when installing or it will leak and cause you another stripdown!