There's only one company that delivers true squirrel proof feeders in my mind! Brome with their squirrel buster feeders are highly successful at deterring our most notorious squirrels at the feeders, saving you money on seed!
SQB1024 Squirrel Bstr Plus w/ Rng
SQB1016 Finch Buster
SQB1053 Squirrel Buster Peanut