4.5x8" tri-fold heavy paper w/illustration of Trylon and Perisphere on front and text including "To Find Point Of Interest At A Glance/1. Look Up Its Key Number In Index Inside. 2. Pull Slide Until This Number Appears In Window On Map. 3. Location Is Then Shown By Red Dot On Map. Additional Information Appears Through Slot On Reverse Side." Opened end has 1.25" NYWF official seal split when opened but attached. Inside is color illustration of "The Brazilian Pavilion." Left side has gw illustration of Boy Scout w/text including "Visit The Boy Scout Camp/New York World's Fair/Boy Scouts Day Thursday June 29, 1939." Inside unfolds again to reveal index of key numbers with alphabetized list of different exhibits throughout the fair. Inside sleeve works similar to a slide rule to allow user to find location of desired exhibit. Slide area has original tin reinforcement along top and bottom to assure smooth use of the sliding device. Back has illustration of building w/text "France/French Overseas Possessions/Pull Slide Out To Key Numbers 87 And 89." Lt. surface dust to covers. Inside is Exc.