The Songbird Essentials Dr. JB Switchable Jar Only 48 oz. for Bird Feeders (SE6023) gives you the option to feed more birds during migration season! Instead of filling up your feeder over and over, what you can do is switch up your feeders. It'll save you more time and can definitely prevent you from interrupting the hummingbirds when it is time to refill the feeder. You can use the base of your Dr. JB Hummingbird feeder. This jar will replace your 32 oz. Jar and meet the needs of your hungry hummingbirds. Product is made of durable plastic that can last for a long time.