Ringtones: M501 model- 58 alarm ringtonesDW520 model-32 ringtones5-level volume control (both models) Ideal for office, retail, and café settings
Working Rang: Motion sensor door chime up to 500Ft,Door bells chimes up to 700Ft;indoor motion sensor alarm detects movement within 16- 26ft range x 110°
Expandable: Each door/motion sensor or receiver can be expandable,you can use them with additional AMHEY door/motion sensors or doorbells.
Easy to Install: Just plug the doorbell receiver(M501/DW520) into any standard outlet and tear the double-sided adhesive tape on the back of door/motion sensor to stick to the door or window.
Alarm Principle: The motion sensor(DW520+P827) can send an alarm to the receiver when you pass through the detection area; The door sensor(M507+D7) can sound a bell when you open the door