Pit Posse PP25724 Motorcycle Dirt Bike ATV 2 Stroke & 4 Stroke Muffler Tail Pipe Exhaust Silencer Wash Plug Kit You are buying One 2-Stroke & 1 4-Stroke Muffler Wash Plug Kit Universal design to fit most all 2-stroke mufflers 2-stroke 14mm smallest point 38mm largest point 4-stroke 33mm smallest point 61mm largest point Keeps water and dirt out of your muffler when washing your bike