This is a hook for hanging headphones on the back of an Ikea JÄRVFJÄLLET office chair. The chair back is a rounded rectangular pipe with a rubber plug in the end. After removing the plug, the Hanger part can be inserted into the pipe and the Lid part can be inserted to cap off the pipe and prevent dust from getting in it. It should be printed as 2 parts without support: the hook can be printed on its side, and the lid can be printed with the flat side down.