Summary: I had an older version of these (3 years old?), the Plantronics DSP-400, and loved them but unfortunately, I damaged them accidentally yanked them really hard when moving them (I had forgotten to unplug them)...no fault of Plantronics…so had to get a new pair. I wanted the same ones and lucky for me, they're making an almost identical version, the .Audio 400. Same thing except for some reason, these feel sturdier, yet smoother. Nice touch.
Summary: Plantronics must have more than one headset with the same model number, DSP400. Although this one seems to work OK, it is not the same as another set I have with the same model number. This has regular speaker and mic jacks, but includes a USB adapter. The other DSP400 I have just has a USB connection. it isn't clear whether or not this has a noise cancelling mic.
Summary: My son gave my wife his Plantronics DSP 400 to try; claiming they were very comfortable and sounded great . My wife and I totally agreed with him, they are so comfortable that you can wear them all day without any discomfort at all. As a result, I purchased 2 of these headsets but when I tried one on it was very uncomfortable.
Summary: Very good to find a quality product that worked out of the box with Ubuntu Linux. Very good sound quality - I would not have had to buy this if I had not stood on the first one that I bought - was relieved to be able to buy this exact replacement.
Summary: I use these with Dragon Naturally Speaking and chose them after checking the list of headsets approved by the manufacturers of the Dragon software. They fit so comfortably and the accuracy of the text written by Dragon that I dictated is much better than with the cheaper headset I used in the past - the set that came with the program. I also like the fact that these fold away so I can carry them around with me.