The Thermos, a vacuum flask adapted for lunch box use, was introduced in 1904. The Thermos, which enabled hot or cold beverages to remain at optimal temperature until lunchtime, became a common component of the lunch box. Lunch boxes have been manufactured using various materials. Typically, children's school lunch boxes are made of plastic or vinyl, while adult workers' lunch boxes are commonly made of metal, such as tin or aluminium, due to the greater need for durability. The aluminium variant was invented in 1954 by Leo May, a miner in Sudbury, Ontario, after he accidentally crushed his tin lunch box. In 1935, Geuder, Paeschke and Frey produced the first licensed character lunch box, Mickey Mouse. It was a lithographed oval tin, with a pull-out tray inside. It had no vacuum bottle, but did have a handle. In 1950, Aladdin Industries created the first children's lunch box based on a television show, "Hopalong Cassidy". The Hopalong Cassidy lunch kit, or "Hoppy", quickly became Aladdin’s cash cow. Debuting in time for back-to-school 1950, it would go on to sell 600,000 units in its first year alone, each at 2.39. While television was experiencing amazing growth during the 1950s, manufacturers saw a potential for sales. Manufacturers grew to include ADCO Liberty, American Thermos (later King Seeley Thermos, or KST), Kruger Manufacturing Company, Landers, Frary and Clark (Universal), Okay Industries, and a number of other producers through the 1980s. The first use of plastics was the lunch box handle, but later spread to the entire box, with the first molded plastic boxes produced during the 1960s. Vinyl lunch boxes debuted in 1959. During the 1960s, the lunch box had few changes. The vacuum bottle included in them, however, steadily evolved during the course of the decade and into the 1970s. What was originally a steel vacuum bottle with glass liner, cork or rubber stopper, and bakelite cup became an all-plastic bottle, with insulated foam rather than vacuum. Aladdin produced glass liners into the 1970s, but they were soon replaced with plastic. In some South American countries, a lunch box is called "", especially among school children, in clear assimilation of the English word "lunch". In India, a lunchbox is commonly referred to as a “tiffin carrier” or a “tiffin box”.