For use with any Droll Yankees threaded base feeder, Perfect for attaching a seed tray, Easily unscrews for cleaning, Sturdy, heavy-duty plastic construction, Hook holds up to 30 pounds, allowing you to hang another seed or suet feeder beneath, Specifications:, Dimensions: 1/2"" - 14 npt (thread size), Mounting: Screws into the base of your feeder, Construction: UV Stabilized Polycarbonate, SKU: DRLLYNK142