Changzhou Esuntech Co.,Ltd. is a commitment to high-quality locates in Jiangsu near Shanghai which is convenient for goods transportation and customer visiting. And we have Electromax Co as the agent  in Seoul Korea. Main Poducts: Buzzer: piezoelectric (piezo) vibration element, piezoelectric buzzer, 
magnetic buzzer, SMD buzzer Speaker: piezo tweeter, mylar speaker, loudspeaker, tweeter speaker, TV speaker, car speaker, multimedia speaker, woofer, sub-woofer, waterproof speaker etc Ultrasonic sensor: for car parking system or distance tester