These larger grommets are for supporting a tuner on the chassis. They fit into a hole in the chassis that is 7/16 in. more or less. These work well for the grommets between the dial/thumb wheel/pushbutton assembly and the chassis on models 39-40, 39-55, and 39-116 (takes 4), and probably the 39-45. They also fit models 20, 70, and 90. Th...