Discraft, founded in the late 1970s by Jim Kenner in London, Ontario, later moved the company from Canada to its present location in Wixom, Michigan. Discraft introduced the Ultrastar 175 gram disc in 1981, with an updated mold in 1983. This disc was adopted as the standard for ultimate during the 1980s, with Wham-O holdouts frustrated by the discontinuation of the 80 mold and plastic quality problems with discs made on the replacement 80e mold. Wham-O soon introduced a contending 175 gram disc, the U-Max, that also suffered from quality problems and was never widely popular for ultimate. In 1991 the Ultrastar was specified as the official disc for UPA tournament play and remains in wide use.