The 44-505 is a 5-Way Stereo Speaker Selector. 

This item allows you to connect up to five pairs of speakers to a stereo originally equipped to support only one or two pair. One or five or any combination in between can be selected to play at once. Note that you do not gain any output power by doing this; what you've got is what you've got (and the further you spread it, the less it covers...). This product is meant for providing background level music in multiple rooms, not running a disco. Power rating (per channel) is 50 watts; A headphone jack and output protection against shorts are also provided.