ADA Racing billet dome includes compression(OR043) and dome top(OR020) orings. Squish relief is .015 inch @ 80.5mm with a 16 degree angle.
Domes are sold individually.
For reference, the stock head is equivalent to 46cc domes.
For '99 models with stock carbs, you need to check your serial# for the correct ignitor. If the serial# is KAW44000 or lower then you need the 44cc dome for premium pump gas. If the serial# is KAW44001 or higher then you can use the 42cc domes for premium pump gas.