As others have noted, sound quality is a hit or miss venture - it depends on the combination of phone and headset. Frustrating, but reality. I use my Plantronics with a Uniden TRU346, I've had to max out the volume on the phone and in both places on the headset to achieve adequate enough volume where no one complains about not hearing me. Fortunately, both the M175 and Uniden have excellent volume control features, otherwise I'd have had to return this headset. The only downside to this is that when dialing, if I forget to turn down the volume before dialing it's too loud, after connecting I then can max the volume - a minor annoyance.I use a business level (read: very expensive) Plantronics headset with amplification module at the office, but that ties me to my desk, when working from home, I use the Plantronics M175, put my phone in my pocket, and can roam hands free for as far as my phone will take me. Plantronics quality of materials, design, construction and sound is among the best. A handy mute button and volume control dial located mid point on the cord makes quick adjustment a breeze. It would have been nice to have had a call end button on the cord, but for this price, it's a deal without it.I actually prefer the shortened boom, my headset at work has a longer and adjustable wire boom, but it gets in the way most times - being bumped by my hand (makes for an audible shock to the other party), getting in the way while taking a sip of coffee, etc., and with the shorter boom on the M175, when my allergies are in full swing, I can hit the mute button and blow my nose or sneeze without moving the boom, and the caller doesn't know what I just did - sounds funny, but think of how often one's immediate needs are limited by being on the phone. Also, Plantronics does a better job than most at eliminating background noise.Buy this unit if your phone has excellent volume control abilities and you want the option of using as a headset or ear setup. Shop around, you'll be surprised at how low priced Amazon is for this unit.