Item Dimensions L x W x H 9.5 x 8.8 x 7.7 centimeters Number of Batteries 1 AA - not included Voltage 12 volts About this item ASSISTANCE CALLER: Ideal as an alarm for those who need help quickly, such as the elderly, children, disabled, pregnant, or sick. Simply press the call button for quick and considerate care without shouting. It can also be used as a doorbell. EMERGENCY ALARM: We can put it in our pocket or use the necklace (included) to hang it around our neck like a pendant. We can also attach it to the bed or toilet with double-sided tape so that our parents or children can send signals in time. WATERPROOF SOS TRANSMITTER: The call button is waterproof. Approved for bed/toilet attachments, approved for meal/soup splashes. And have it installed in the toilet, applicable to the following places: home, nursing home, clinic, hospital, etc. EASY INSTALLATION: This caregiver pager system supports pairing between multiple receivers and transmitters. We can adjust the kit to our needs.