Details
It's a simple, inexpensive feeder.
Its mesh is just the right size to let the birds pull the seeds out one at a time, but to prevent a cascade of wasted seed on the ground.
Water drains right through it, so the seed stays fresher. The mesh is made of metal, so squirrels don't have much luck with it.
Although the manufacturer says it's designed for black oil sunflower seeds, here at Birdwatching Dot Com we fill it with hulled sunflower hearts. The birds just go nuts over them. It's always mobbed with goldfinches, woodpeckers, titmice, and chickadees. In summer, rose-breasted grosbeaks visit it every day.
Because hulled sunflower seeds are smaller than the ones still in the shells, some seeds fall out. Down below, the juncos feast on those.