Excellent Material: Made of high quality nylon plastics with flame-retardant materials, high temperature resistance, no odor, 3 way Y shape connector durability. Adjustable Valve Flap: Y shape outlet connector diameter is 75mm/3inch, with adjustable valve flaps to control the air volume as needed. Size: Diesel heater duct connector accessories inner diameter 71mm/2.8inch; outer diameter 75mm/3.0inch; Y shape connector size 19.5x10x15.5cm/7.68''x3.94''x6.1''(L*W*H). Easy Installation: No need to drill or cut, install directly, the process only takes a few seconds. Additional outlet for existing heater, efficient split the flow of warm air from your heater, direct compatible with the original heater duct. Applicability: Suitable for most air parking heaters such as Webasto Eberspek and Propex diesel heater.