A fish bite alarm can be very useful. If you are fishing in dim conditions you not otherwise notice if you have a bite. They can also be handy if you have a selection of rods to manage or if you are likely to fall asleep! This one has a bright light and makes a noise and there are different modes of sensitivity, tone and volume so you can set it precisely to your needs, It is powered by a 9v battery. It is easy to use and you get three alarms in this set together with three coloured fish swingers.