the center shaft support member 17 the center mast support frame member 6 runs from a semi circular channel guide 7 on the sliding carriage 8 through the center mast slot hole 5 in the fabric main sheet fig7 and 8 illustrate a sliding carriage 8 located on the center shaft support frame member 17 the sliding carriage 8 is constructed in a hollow shape so as to allow it to slide back and forth on the center shaft support frame member 17 similar to the support frame members the sliding carriage 8 is comprised of lightweight metal plastic or composite the sliding carriage 8 includes a spring loaded pop pin mechanism 22 which allows the sliding carriage 8 to be secured to two specific locations on the center shaft support frame member 17 with drilled holes into which the spring loaded pop pin mechanism 22 will engage when the sign assembly is in a collapsed or expanded state the spring loaded pop pin mechanism 22 will engage in the center shaft support frame member forward hole 25 when the sign assembly is in its expanded or deployed state and in the center shaft support frame member rear hole 24 in its collapsed state upon engagement of the pop pin mechanism 22 into either.