4 Modes:Sound only, flash only, sound & flash, sound & light on.Light on mode can turn into a night lightMemory function:After the power is turned off, the music set .No need to set music againSelf-powered doorbell that requires no battery,'t worry if the battery has power, so 't miss important visitors lights, loud ringtones. Especially suitable for the elderly, pregnant women, housewife.Self powered buttonThis button uses kinetic energy.No battery required4 modes ( features)1.Sound only2.Flash only3.Sound & flash4.Sound & light onLight on mode can turn into a night lightVoltage: AC100-240VPlug Type:EU Plug,it applies to Indonesia, , , , and so on.Receiver :1Colour:BlackMaterial:plasticPackage Contents:1 * Button 1 * ReceiverOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.