It's a v shaped earphone holder as a keychain, it includes a hole for the jack on one of the faces and a other holes on the other side, for the earphones. It has a hole for the keyring on the top side. It is a very simple design with no extruding parts.

To use this product, the wire is wrapped around its body (after inserting the jack from the inside out) and the headphones are put in place. 

The keychain in 5.3 cm tall, 3 cm wide and 2..5 cm wide.