frame 12 includes a pair of ground engaging members 14 pivotably connected to an upstanding frame member 18 the lower end of the frame member 18 has adjustable outriggers 16 the frame member 18 may have a transversely disposed brace 20 as shown more clearly in fig2 a socket 22 is fixedly secured to the frame member 18 and brace 20 socket 22 is open at both ends and may be in the form of a rectangular tube having one side welded to the frame member 18 and brace 20 conversion apparatus or sign holder designated generally as 24 and shown in fig2 is provided for converting a sign panel rigidly connected to the support frame 12 so that the sign panel may be wind deflectable the sign holder 24 includes a flexible resilient strip 26 strip 26 has a width substantially greater than its thickness so as to have two major faces the preferred embodiment is to provide the strip 26 with uniform thickness see fig2 and 4 further the preferred embodiment is to use a strip 26 made from 30 polymeric plastic material such as a polyester containing 10 filler by weight and reinforced with 70 longitudinally extending fibers of fiberglass strip 26 is non corrosive and other resilient plastic materials as well as resilient metal strips may be used a connector means 30 is coupled to one end of the strip 26 such as the upper end thereof the connector means 30 includes a casing 32 through which the strip 26 extends casing 32 is open at both ends and has a width which is greater than the thickness of strip 26 a pressure plate 34 is juxtaposed to.