As I said I was having some luck finding rare nail knobs etc. when I came across this large knob. It measures 2" X3" and is marked MICO (Moglodore Insulator Co.). This company is hard to find but I have several pieces made by them. Pictured with this knob is the no tie style made by them. On the left side is marked CLINCHD misspelled and Pat Appl'd For on the bottom. On the right is marked normal CLINCHO and on the bottom Pat Appl'd For. Either way they are rare to find.