Compact, solid, non-slip chrome buttons, a stereo output (and therefore able to place it between the output soundcard of a PC and the amp, for example) with switch "mute". The sound is very good, the gain is powerful, short but good!

Edit the 26-10-2008:
Again good headphone amp, for cons avoid using it through to the speakers because the output lines are not passive, not entirely neutral.

Edit the 12-5-2011:
2 knobs scratchent abominably