C20 Elderly Monitoring Alarm Home EU Plug Wireless Caregiver Pager Smart Call System Senior Personal Buzzer Alarm 1 Call Button and 2 Receivers - Black Emergency button screwless chuck design,it's waterproof and dustproof even without a rubber ring Receiver: AC socket,EU plug supports 110-240V voltage The SOS call button uses a CR2032 battery SOS button receiving distance: open area receiving distance up to 80 meters 38 Songs to choose from. 4-level volume adjustable (including silent mode) Easy to use. Just plug the receiver into an outlet,all the seniors/disabled/bedridden need to do is push the panic button to ask for help It comes with a lanyard,the wearable call button can be hung around the neck,and also can be attached to the walker/chair/bedside Note: The transmitter shown in the picture is for rendering only (not included). The wireless signal can be affected by obstacles. The more obstacles,the more serious the loss of signal. Specification: Call button size: 60x34x11.5mm Receiver size: 90x56x20mm Package included: 2 x Receivers 1 x Call Button 1 x English User Manual Other things not included