ONE CONNECTOR LIKE SHOWN

Look carefully, center pin is Male and one curved blade is wider than other (there are a lot of varieties of these, so study picture and compare to your mating P&S or Hubbell plug before bidding)

3 conductor (generally used for AC plus ground)

outer diameter (round chasis hole size) would be around 1 1/4 inch

diameter of mating connector would be around 1 1/8 inches