These feeder pails are an economical alternative to hive-top feeders. They offer most of the benefits (feed is only accessible to the hive getting fed, feed gets warmed by the heat of the bees below) of our hive top feeders while being cheaper and easier to store (and don't need to be sealed!).
Pail feeders are meant for use with wooden inner covers that have a hole in the center: fill the pail with syrup, secure the lid, invert of the opening in the inner cover, and place an empty box above the inner cover to protect the pail. Alternatively they can be placed directly on the top bars of the hive and protected with an empty box (fits in a medium super box).