Keep your feathered garden visitors happy with Perky-Pet Ready-To-Use Hummingbird Nectar. Formulated with 100% sucrose, this nectar is the perfect energy source for hungry hummingbirds! Easy to use: just add straight into your feeder. No boiling, mixing, or refrigeration needed.Manufacturer model #: 239. Formulated with 100% sucrose Easy to use: just add to your feeder No boiling, mixing, or refrigeration needed