I have a feeder that seems to be 100% squirrel free. it is the tube type but the spots where the birds stand are spring loaded and will drop away if a squirrel or even a hevier bird stands on it. Never had a problem. The brand id Droll Yankee Dipper. It works great
Droll Yankee Dipper
I also have banned Blue Jays. Their screeching call makes me want to grab the shotgun. Have my Oriole feeders out now. So far no luck.