This slim, attractive and affordable device fits poles up to 1 inch in diameter and stops squirrels and raccoons from climbing a feeder pole. When an animal climbs past the Tough Bird Feeder Guard it receives a static electric training pulse powered by a single 9V battery. Though effective, it’s harmless to the animals. They quickly learn not to climb the pole. The pole and feeder are safe for humans and birds to touch at all times.