This 1-meter Combustion inlet Air Pipe is designed for Eberspacher heaters, including models like the Airtronic D2, S2 D2, D4, and D3LC Compact. It is also compatible with Webasto heaters such as the Air Top 3500, 5000, 3500ST, 5000ST, EVO 3900, EVO 5500, EVO 40, and EVO 55. This is a genuine quality Eberspacher repair part that fits most Eberspacher Espar heaters. It is also suitable for many Webasto heaters and can serve as an upgrade for Chinese heaters. The pipe has a 25mm internal diameter.