Built in squirrel guard prevents squirrels from hanging down and reaching seed. Spring-loaded perches collapse under the weight of the squirrels, preventing them from becoming a foothold for the squirrels. Turn-key locking mechanism on the underside of the roof prevents squirrels from accessing seed. Unique Funnel Flip-Top roof design creates a 38 percent wider opening with a built -in funnel in the lid of the feeder for the easiest filling with less spill! 2-in-1 technology allows feeder to be used to feed a wider Assortment of seed; thistle inserts included. Easy Clean technology allows feeder to be easily disassembled for cleaning.