Build in anti-interference design, avoid the interference between users. Mini size and beautiful appearance.52 turn songs for your selection. Especially suitable for office building, household, factories, tourism and other places, a wide range of uses. Widely used, not only as a patient care, it can be used for special purposes, such as liaison, ordinary , paging, notification, etc. Convenient for Carrying, The with lanyard can be carried in a pocket.Just pressing the SOS button will cause the receiver to a loud sound. Description: Build in anti-interference design, avoid the interference between users. Mini size and beautiful appearance.52 turn songs for your selection. Especially suitable for office building, household, factories, tourism and other places, a wide range of uses. Widely used, not only as a patient care, it can be used for special purposes, such as liaison, ordinary , paging, notification, etc. Convenient for Carrying, The with lanyard can be carried in a pocket.Just pressing the SOS button will cause the receiver to a loud sound. Specification: Battery: 3V 2032 battery SOS Button: 90-250V(US Plug) Size: 8.1X8..5cm Package Includes: 1 X (Remote Control) 1 X Receiver(SOS Button) 1 X User Manual 1 X Lanyard Note: Transition: 1cm=10mm=0.39inch Please allow slightly 0-1cm difference due to manual measurement. Colors can appear different depending on light and how the listing is viewed. Thanks for your understanding and attention.Wish you a pleasant shopping experience