Perky-Pet 121TF Etched Hummingbird Top Fill Push-Pull 16oz Plastic Hummingbird Feeder Patent-pending Push-Pull technology for effortless refilling - just push, pour, then pull-and-lock. Features an easy to fill wide mouth top and an advanced "sports bottle" like function to facilitate replenishing the nectar Clear plastic reservoir makes it easy to monitor nectar levels in this 16 oz. hummingbird feeder. Four attractive primrose feeding ports on the base of the feeder The Top Fill Hummingbird Feeder lure birds in pursuit of sweet nectar-providing you with hours of joy as beautiful Hummingbirds flock to your feeders.