A hot shoe mount flash in production in the 1980s. Ye Olde Photographer acquired this
for use with his Canon A-1. Like the 177A, this is of the "thyristor" variety which quenches
the flash based on light sensed by a photocell in the gun. It has two power ranges and
can be operated as full-powered manual. Happily, it works and is still in occasional use.