The Droll Yankees Suet Link screws into the base of most Droll Yankess tubular or caged bird feeders. In addition, it can be used on the X-1, H8-2 and many other brands using a 3/4" screw. It is an excellent solution for hanging an additional feeder such as a suet feeder or hummingbird feeder to a seed feeder. Please note, the suet link is not compatible with the Flipper, Tipper, Dipper, or Whipper.