Low battery reminder; our nurse call system will remind you the low battery; you can say goodbye to the frustration of running out of battery; take the fear away from your loved ones of not being heard in an emergency ^^ Removable battery; the elderly monitoring assistance supports 2 AAA batteries; which is very convenient to replace when it is out of power; and you don't have to worry about not being able to buy suitable batteries locally ^^ Easy to expand; each screen receiver host can add up to 999 call buttons; you can add the call button according to your needs; and each call button can also pair with many receivers ^^ 6 working modes to choose from; room number or bedside number can be set; just press the button; you can quickly find the patient or customer in need; meet the needs of all hospitals; clinics; nursing homes; restaurants; hotels ^^ Working distance; open area working range up to 656 ft; signal transmission distance; high sensitivity receiving technology; the product's signal stability