... Transmitter button;•Just pressing Remote Transmitter button to trigger Receiver to beep,color-coded helps to use more easily;•Loud Volume:85- ... 315/433Hz,keep stable,strong anti-interference;•Automatic beep continuously to warn battery is low. ADVANTANGES:•Facotry Direct Sales,at ... ,just press Transmitter button,beep & flash mode helps to find things easily;•Portable,can be hung with keychain,or ...