CANNOT WORK ALONEThe receiver alarm has to pair with the CallToU/transmitter. And one receiver can pair up to 55 buttons. Easy to Use and CarryJust Put 2 AAA Batteries in the Receiver and Switch on.The Nurse call system will Ring and Vibrate and Flash when Press the Call Button.Choose vibration and Ringtone(5 Volume Levels from Long RangeOperating Range is 500+ Feet in Open Area. Each Wireless Portable Receiver Can Work with 50pcs Call Buttons.Each Transmitter Can Pair with 50pcs Receiver and be Set to Different or Same Music. Low Power IndicatorEach unit of this Old People Pager Alarm has a built-in rechargeable battery with low power indicator function. It will remind the caregiver to charge the unit in time without worrying about the call button not working in an emergency. Portable Pager-The Receiver can be Carried Around in a Pocket. or it can be Fixed on a Belt and Placed on a Table. The Elderly Pager can be Placed in your Pocket or Hung Around your Neck. About Shipping: All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances.Any questions, please feel free to contact us During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours, wish you a happy shopping Thanks for your cooperation and we'll make you feel satisfied.