Description: 3.5mm Mono Plug (male) to 3.5mm Stereo Jack (female) Adaptor - Gold Plated

Q1: If my equipment is mono, will this plug change it so i hear stereo out of the headphones?

A1: You can think of the plug as a 'splitter' that takes the incoming mono track and sends it to the 2 outputs that your stereo plug can read. The sound is still a true 'mono' signal that is now played in both earpieces. Not stereo, but same sound in both ears.