Thank you for looking. These are a set of four Burns-type aluminum knobs for a John Lennon 1958 Rickenbacker 325, final version specification, purchased at a specialty store a long time ago. They are the type that are tightened with a hex wrench from the side. The fifth photo shows the actual item used by the artist, and it looks quite similar. The guitar itself has been sold, so only the knobs are being offered. Thank you.