Delphin SHOCKER is a sensitive bite alarm indicator. The alarm goes on everytime the fish shakes the rod. Indicator is fixed to the rod by a rubber strap and because the backside has been designed to match the shape of the rod, it stays firmly on its place. You can set 4 different alarm tones and 4 different volume levels. The light indication lasts for 20 seconds after the bite. Delphin SHOCKER is powered by 3 x LR44 batteries.