For 400hz mechanical buzzer, everyone has different special concerns about it, and what we do is to maximize the product requirements of each customer, so the quality of our 400hz mechanical buzzer has been well received by many customers and enjoyed a good reputation in many countries. HONGCHANG(CHANGZHOU) ELECTRONIC CO.,LTD 400hz mechanical buzzer have characteristic design & practical performance & competitive price, for more information on the 400hz mechanical buzzer, please feel free to contact us.