Quoting Pete Turnbull <pete at dunnington.plus.com>:
  I don't think you mean C5 (or C6).  That's a
3-pin, the one sometimes
 called "mickey mouse ears", and one of the less-common types.  I mostly
 see it on Toshiba laptop power supplies.
 C7 (cord connector) and C8 (inlet) is 2-pin.  It's the one often
 referred to as "figure of eight", and the only common 2-pin. 
https://en.wikipedia.org/wiki/IEC_60320