Changzhou Yongyin Electronics Co., Ltd. was established in 2000, covering an area of 10000 square meters. It is a professional manufacturer of electromagnetic and piezoelectric buzzers, speakers, mobile phone micro speakers, nickel alloy substrates, and microphone heads (electret microphones). The company currently has 300 employees. The company has established an advanced engineering development department to meet the special needs of different industries for the design of electroacoustic products. From the end of 2003 to 2004, all products of our company were among the first in the industry to pass SGS environmental certification. We currently supply a large number of RoHS compliant electroacoustic products and established a cooperative relationship with Hitachi Electric in 2005, further improving the overall quality of the company. In 2006, the company launched multiple small mobile phone SMD patch buzzers and speakers, and supplied them in bulk with multiple mobile phone OEM companies. In 2008, we developed an ultra small 5 * 5 * 1.9mm SMD patch buzzer and obtained the supplier qualification from Hitachi in the same year; In 2009, we were the first to develop the smallest SMD patch buzzer in China with a size of 5 * 5 * 1.6mm, filling the gap in the domestic market. Entered the smart meter industry in 2010 and...