We have a Triple outlet plug Sylvania nos Vintage item.  It is brown in the original package.  I do not advise to use this as I am not sure it would not overload a circuit.  It measures about 2 1/2" in L x about 1 1/2" in D with the metal prongs being about 3/4" of this measurement.  I believe it dates from around the 1970's.

Triple outlet plug Sylvania nos Vintage

$16.95Price