A seal which is easy to replace, for example because the old one is leaking, or when replacing the chain tensioner. Tip: something suitable sealant can not hurt. There are two versions, these seal !!! It is important to VIN !!! from / to / ab.Mein vehicle has a Veitildeckel plastic, this seal was appropriate. Some experience in the exchange is necessary, not the one still unscrewing the air duct! lol