Mast radiators can also be built as free-standing lattice towers, wide at the bottom for stability, narrowing to a slender mast. The advantage of this construction is the elimination of guy lines and thus reduction in land area required. These towers can have a triangular or a square cross section, with each leg supported on an insulator. A disadvantage is the wide base of the tower distorts the vertical current pattern on the tower, reducing the radiation resistance and therefore the radiated power, so guyed masts are preferred.