They can be used on the HummBlossom Feeders
12 tips per pack Item #384

Nectar Guard tips easily slide onto the feeding ports on the underside of the feeders cover. The flexible membrane in the center of each tip easily opens when hummingbirds insert their beaks to feed and close up tight when beaks are removed. These create a barrier flying insects can't penetrate. Nectar Guard tips are backed with a one-year guarantee.