DO i have to purchase an e-vignette for a trailer/caravan?

DO i have to purchase an e-vignette for a trailer/caravan?

When the total weight of the car + trailer/caravan composition exceeds 3.5 tonnes, then the purchase of a Category 3 e-Vignette is obligatory. The validity period of the trailer/caravan vignette may be different than that of the car.