The Plantronics MX150 is an old, old model. That's a given. (The earliest reviews of this product date back to 2003!)My first cell phone, over 10 years ago, was a Verizon flip-phone. My first (and only) headset I used with my flip-phone was the Plantronics MX150. (When packaged for Verizon the price for the MX150 was a crazy $30.)Not too long ago I finally gave up my beloved flip-phone and "graduated" to a smartphone. I searched and studied and read reviews of various bluetooths. And I didn't like any of them. How was I ever going to find a headset for my smartphone that I liked as much as the one I used with my flip-phone? Then I discovered I didn't have to. With an inexpensive adapter ($1) I could connect my "old-school" MX150 to my "new-school" smartphone!Admittedly, the MX150 is not perfect. I sense many of them sold on Amazon are not OEM (they are a cheaper, knock-off version). They do break easily. I have broken several ... but I like them so much I keep using -- and ordering -- them. At $5, I consider it worth it.I am probably harder on my headset than most. I work 12 hour shifts. Via my smartphone, I listen to talk radio the entire time. The sound quality is great. And, when I do make/receive an occasional phone call, the sound quality is never an issue.SUMMARY: I have used the Plantronics MX150 for over a decade -- both with a flip-phone and a smartphone. My only concern is this: what will use when this old model is finally no longer available?