Usage Tips:Features: brand and Impact resistance, corrosion resistance and flame retardant. Mainly used for 2KW diesel- air heater. Heat & cold, diesel- heater air duct Webasto-, Eberspacher, household, planer, etc. Suitable for any 42mm outlet hose. The length is for cm and can be extended to 80 for cm. Specifications: Material: aluminum foil + plastic Colour: Black Pipe inner diameter: 42mm/1.65in Before the tube is stretched: 32cm/12.59in After the pipe is stretched: 80cm/31.49in Vent size: 77mm/3.03inx62mm/2.44in Outer diameter of vent: 42mm/1.65in Application: air for diesel heater 5000W 4 holes, air heating heater/car/truck/ship/heavy machinery/agricultural machinery/industrial machinery, etc. Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings. Package includes: 4x Heating Tube 4x Vents 8x Clamp