Two screws like the one in this picture, in conjunction with two thumbscrews and the flange, hold the resonator in place on the banjo pot. In this photo we can see that the screw has been repositioned two times for some reason. This banjo is thought to be a 1930s era Slingerland. The Slingerland Musical Instrument Mfg. Co. was based in Chicago, Illinois and was owned and operated by H.H. Slingerland. The company changed names several times, including The Slingerland Banjo Company, Slingerland Banjo and Drum Company and others.