Once the magnetic pull-switch is removed the alarm sounds on this tamper-proof pull-cord alarm by Drive Medical. The pull-switch which includes a convenient On/Off switch activates from any direction and adapts to various situations with a cord that adjusts from 28 to 58 . The unit mounts easily on a bed or wheelchair - even on a patient s clothes thanks to an alligator clip. Volume adjusts from 97 to 103 dB on the alarm which requires one 9V battery (included).