Exhaust Lagging 30mm Internal Diameter. Sold per meter.Suitable for:Thermo Top E & CAir Top 2000 modelsAir top 3500 & 5000Air Top EVO 3900 & 5500This product is designed to sleeve the heaters exhaust pipe to protect the user from burning themselves if they come into contact with the exhaust during the heaters operation.This product must be used for all inland waterways craft for compliance with the Boat Safety Scheme Examination.