Feeder Fresh Nectar Defender is an all-natural product that protects the freshness of hummingbird nectar and stops spoilage. It is bird-safe and works using a micronutrient naturally consumed by hummingbirds in their diet of nectar and insects. Nectar Defender will protect your nectar for weeks, and hummingbirds will enjoy fresh nectar every time they visit your feeder. One bottle lasts an entire season. Contains no artificial preservatives or dyes. Once you try Nectar Defender, you will never want to feed hummingbirds without it. Patent pending. Made in the USA.