OPERATING INSTRUCTIONS:
"The symbol "0" of a switch indicates the "off" position of a
switch".
"For appliances with a polarized plug (one blade wider than the
other):
To reduce the risk of electric shock, this plug is intended to fit
in a polarized outlet only one way.
If the plug does not fit fully in the outlet, reverse the plug.
If it still does not fit, contact a qualified electrician to install the
proper outlet.
Do not modify the plug in any way."
"Foot Controller Model 21371 for use with Sewing Machine
Model 385. 19000xxx."
xxx - represents numbers 000 through 999.