The EAADPT-KIT from Shure is a headphone adapter kit that provides you with flexible connection options for almost any pair of headphones. The airplane adapter allows you to convert a standard 3.5mm mini plug into a dual-prong plug for use with in-flight entertainment systems. The 1/4" adapter allows you to connect a 3.5mm plug to pro-level audio gear.
The in-line volume control has a 3.5mm jack for plugging in your headphones, and a 3.5mm plug for connecting to an MP3 player, CD player, or other electronic device. It then allows you to make on-the-fly volume adjustments without having to take your player out of your pocket or bag.