... optional,use battery,easy use,sound activated,factory offer baby monitor,wireless baby camera,audio baby monitor,315Hz/433Hz optional, ... Once baby is crying or other sound,Receiver will be activated to sound imitated baby crying;Sound Level: 92±5Db;Frequency: 315MHz ... ,SHENZHEN QIYAO PLASTIC & ELECTRONIC CO.,LTD are a professional manufacturer in a wide range of Audio,Electronic and Digital devices in ...