Now just 4099 rrp 5495 save 15one of the best and most effective fox deterrent devices available to the market 125 square metre 1 350 sqft coverage and inaudible to humans harmless to foxes and can be powered by a 9 volt battery or a mains adaptor for increased performance average battery life 2 3 months however mains adaptor recommended if a lot of people or creatures pass by as the alarm volume is increased by 30