Marinus van Dam, product developer and plant manager for the company, oversaw the development of Jelly Belly jelly beans. By the 1980s, many flavors had been developed. In 1980, Klein sold his interest in the Jelly Belly name. "David Klein sold the Jelly Belly trademark to Rowland for $4.8 million, paid in monthly installments over 20 years, which Klein split with a partner." The Jelly Belly trademark was registered August 3, 1982. The Mr. Jelly Belly character was developed in 1983. Prior to the development of the character David Klein called himself "Mr. Jelly Belly."