The silo feeder has a guard which keeps debris, shells, and hulls from falling outside the cage. The feeder prevents "hull build up" on top of the seeds. As new seeds fall of the silo on to the tray, they push the old hulls out.
Base screws into the cage to guarantee a secure fit on horizontal or vertical barred cages. Extra tall to double the seed. Easy to clean. Dishwasher safe. Color of product may vary.