A circumcision device consisting of a metal bell placed over the glans (requiring a dorsal slit in the foreskin first) and a flat plate with a hole in it placed over both, to define the position of the cut. They are brought together by a screw to apply circular crushing and fusing force at the position of excision.

It is estimated that over 75% of circumcised American men born between 1950 and 1980 were circumcised with a Gomco clamp or similar device. The presence of a brown ring, typically one inch behind the corona, typically indicates a Gomco circumcision.  The clamp was invented in 1934 by Hiram S. Yellen, M.D. and Aaron A. Goldstein. The name of the device comes from the GOldstein Manufacturing COmpany, which later became the Gomco Surgical Manufacturing Co.  Also referred to as a Yellen clamp.

Image Source:

www.en.wikipedia.org/wiki/File:Gamco.jpg

Image Source: www.circlist.com/instrstechs/gomco.html