The first recorded patent for a wireless microphone was filed by Raymond A. Litke, an American electrical engineer with Educational Media Resources and San Jose State College, who invented a wireless microphone in 1957 to meet the multimedia needs for television, radio, and classroom instruction. His U.S. patent number 3134074 was granted in May 1964.[9] Two microphone types were made available for purchase in 1959: hand-held and lavalier. The main transmitter module was a cigar-sized device which weighed 7 ounces (200 g).