Trampolines are always measured as the diameter of the outside metal ring. Please ensure that you have measured your trampoline correctly, BEFORE purchasing this item. This cover is meant to keep debris off the trampoline it is not designed to keep it dry. The cover comes with a drain hole in it so that rain water can escape through the cover, preventing it from building up on top of he trampoline mat (the weight of the water would cause the mat to stretch and cause damage).