These cap and ladders snap onto our medium in hive feeder, product M531M (sold separately.) The cap covers the opening of the feeder, except for two spaces. The bees can climb into the two open spaces and hang onto the ladders, which go all the way to the bottom of the feeder. This helps reduce drowning.
Note: Feeder is NOT included. Must be purchased separately. Feeder is item number M531M.