The most famous player to wear this mask was the Raiders QB Ken Stabler.  The supermask (made of Stainless steal) was field tested for many years before the catalog unveiling in 1978.  During this prototype and testing period Dungard ship these masks to teams all over the NFL.  The Raiders did not receive an OPO as seen in the above left photo.  Stabler had his equipment manager Dick Romanski hacksaw out the center bar of an NOP.  Not very esthetically pleasing to our eye, but it wasn't our eyes that Ken was concerned with.