Our newest hummingbird feeder the HummZinger Ultra combines patented Nectar-guard tips with a built-in ant moat. Nectar-Guard tips are flexible membranes attached to the HummZinger Ultraís feed ports. These unique tips prohibit entry from flying insects while allowing unrestricted feeding by hummingbirds. Also, the built-in ant moat stops crawling insects in their tracks before they can reach the nectar. These two patented features combine to give our HummZinger Ultra the ultimate in protection from both flying and crawling insects while you can enjoy the hummingbirds. Lifetime Guarantee 12oz capacity