I bought one of these from a studio engineer, and use it at home, running music from my hard drives through my laptop, via a Motu 828 MKII soundcard and a pair of Beyerdynamic DT770 250ohm headphones, and also for listening to audio files created myself via Cubase.
Needless to say, up to 4 people can listen to the same output thanks to this device, and each person is also able to choose a volume appropriate to their personal preferences.
I find it allows me to listen to audio much louder than the laptop alone would ever allow.
An invaluable piece of kit, and great value for money.