... two receiverControl distance :10~30mSound:90-95dBFrequency:433 MHz Battery:Please advise .Battery life :6 months(an average of five times daily ... light flashing. Using one piece of CR2450 button battery, power voltage 3V/capacity 600mah,Battery using longest time is up to 3~5 ... look for several receivers(goods),using 1 piece of 12V27A battery, after 6-10 months, please pay attention to power energy ...