Sapphire Labs Nectar Defender

Nectar Defender protects the birds and prevents nectar spoilage naturally up to 2 weeks, even in hot weather; They will enjoy fresh nectar every time they visit the feeder between cleanings; Micronutrient copper has shown to be safe for hummingbirds in long-term studies of hummingbirds’ diet conducted by University of California Avian Scientists, and at zoo and wildlife rehabilitation organizations to successfully maintain the long-term health of their hummingbird colonies for years at a time; 24-4 oz bottles/case.