This feeder holds about 1L of syrup and goes inside your hive over a crown board so its perfect for flow hives. 

As its inside your hive so there can be no problem with ants or robber bees stealing the syrup. It's a ladder style feeder so the bees climb down a ladder to the syrup and are less likely to drown. for a video of this in use click here https://www.youtube.com/watch?v=0dCPvi0iCaQ