The cruelty of the manufacturer, efficient, maintenance-free electronic yard protector keeps the birds away from your property without messy or expensive chemical solutions. Independent laboratory testing has proven sound technology to a very effective form of fighting birds. Use it to repel pigeons, woodpeckers, swallows, starlings, sparrows and other creatures. Meadows cover: it uses up to 900 Square Feet: balconies, terraces, courtyards, gardens, porches, buildings, greenhouses, and more! Adapter comes with 50 feet or extension can work with 4 C batteries motion detector mode. Human, effective, maintenance-free electronic yard protector keeps the birds away from your property without messy or expensive chemical solutions. Independent laboratory testing has proven sound technology to a very effective form of fighting birds. Use it to repel pigeons, woodpeckers, swallows, starlings, sparrows and other creatures. Coverage: up to 900 square meters U