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).