Squirrel Buster® feeders are the ultimate solution to stop squirrels eating your bird food. All Squirrel Buster® feeders work in the same way - when a squirrel lands on the feeder its weight automatically closes the feeding ports, denying access to the food inside and not harming the squirrel in any way. These high-performance feeders are 100% effective when hung with at least 47cm clearance all around, forcing the squirrel to climb on to the feeder and trigger the closing mechanism. They have also been designed to dismantle easily for filling and cleaning. This 4 port seed feeder has an adjustable weight mechanism to exclude larger birds as well as squirrels. We recommend hanging the feeder atleast 3 feet away from other Buster feeders.