This 8ft trampoline cover fits straight onto your assembled trampoline frame by a PP rope. Made from PE 100g/m x 100g/m, keeps the trampoline clean and dry. How to measure your trampoline- Your trampoline should be measured across its diameter, that's across the top of the trampoline from one side to the other, including the existing spring padding. The size will most likely be 8ft, 10ft, 12ft, 13ft or 14ft, although other sizes do exist. If you are not sure exactly which size you require feel free to contact us with the diameter measurements.