Original 8x8.5" illustrated sleeve (featuring images of Superman, Flash Gordon, Green Hornet's Black Beauty car, Mandrake the Magician, The Shadow and The Lone Ranger) contains 8x8" square, thin vinyl flexi-disc 16-2/3 RPM records, a speed used almost exclusively for spoken word content, particularly the "talking books" used by the visually impaired. For this reason, the inclusion of this speed was compulsory for record players in some countries for many years, despite the scarcity of the records themselves. Set was issued in the 1970s by Eva-Tone Soundsheets for $3. Each is double-sided and includes - "The Shadow" (1937), "Superman" (1945), "Captain Midnight" (1947), "Flash Gordon" (1935), "The Avenger" (1941), "Mandrake" (1939), "The Blue Beetle" (1943) as well as theme songs from "The Green Hornet, The Lone Ranger, Dick Tracy" and "Hop Harrigan." Sleeve shows some scattered wear and has even, lt. aging. Records appear unused and Mint. A rare set w/great multi-character appeal.