The squirrel buster classic is designed to deter marauding squirrels and large birds from emptying the contents of your feeder the four ports on this innovative seed feeder close as soon as anything weighing over 115g hangs from or lands on it the average weight of an adult grey squirrel is 400 600g the metal mesh cage over the feeding tube will also appeal to clinging species as well as those that prefer to perch to feed when placing the squirrel buster classic in your garden be sure tha