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 Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-DIMEANI official store