The Nash Siren R4 Alarm is designed for the modern sport of carp fishing. The Siren R4 responds to every positive indication of carp activity, screening out non-events with its Intelligent Sensing. The Nash Siren R4 3 Rod Set contains 1 x R4 Receiver and 3 x R4 Alarm Heads. The R4 Alarm Heads are powered by 2 x AAA batteries (not included) and the R4 Receiver has an internal USB-C rechargeable battery.