This is a VERY common regulated 12 VDC 2000mA output power supply used for many common gadgets.
Oh electricity. You're so tricky. You'd think you could just stick a straw into an outlet, let all those electrons pour out onto your device of choice, and BAM! FUNCTIONING GADGETS! But apparently it doesn't work that way. Instead you need one of these fancy switching power supplies. This popular regulated 12V DC supply is reliable and compact, giving you the current you'll need for most kinds of music players, portable media devices/TV's/DVD players, small amplifiers, office devices, battery chargers, and a wide range of do-it-yourself death rays (we're joking about this last part... mostly). This unit has an inline filter, which cuts down the AC line noise and interference that tends to bother sensitive audio systems. It also has a 6ft detachable input cord and is safety approved by such fancy safety approvers as UL and CE.