Features: Perfect fan for car, truck, tent, RV, sleeper cab, SUV, ATV, delivery van,etc. Provide a freshs air environment. Dust cover design,effectively prevents the dust. Adjusatble height to fit your different installation requirements. Top mounting typed, which is space-saving. Installation: Opening size:Φ118mm(the extension pipe can use a hose with an inner diameter of 120mm or a PVC pipes with a diameter of 110mm) Out of the roof:height-53mm Installation thickness: 80-160mm adjustable Connection:Red wire(+);Black wire(-)