Ningbo Yinzhou Acousto-optic Electronics Co., Ltd. was founded in 1998 and is a manufacturer of electret microphones (microphones) and 2SK596 and 1109 transistors. The company covers an area of 4,500 square meters. The construction area is 3,500 square meters. There are more than 350 employees, including 25 engineers and technicians. It can produce various models and dozens of varieties of "Sound and Light" electret microphones (microphones), with a monthly production capacity of 30 million pieces. The product is highly adaptable and can be widely used in telephones, tape recorders, mobile phones, voice-activated toys, computers and other audio-electric conversion products.