There are two main types of Frame holders:
Metal frame holder – These usually hang on the side of a Box to keep the frames close to the hive.
Wooden frame holder – These are usually home-built and since everyone has their own unique way of making things no two will be the same design but for the most part they are just boxes with legs on them to keep the frames off the ground.
This is one side of a metal frame holder, there is a second identical piece that holds the other end of the frame when in use. The hook shaped part on the left hangs on the side of your box, while the bar going off to the right is what the frames actually sit on