1.220V door chime switch 2.Application:Hotel,Home,KTV,etc 3.Match ... Room NO.doorbell,D.N.D and so on Door chime switchThere are two kinds :1.Weak current(Low voltage12V) ... door chime:Use together with whole system(Bedside control panel,Master control ... voltage is 10V.2.Heavy current(High voltage220V) door chime:Don't need to use together with whole system,and ...