Not the same as the 510
I thought this would be an improvement over my faithful Voyager 510 - it was not - the volume had to be mid level to hear (the 510 is fine at the lowest setting) and was uncomfortable in the ear compared to the 510's sponge earpiece.
<br />Also, there is also no mute feature on the 520.
<br />I wound up losing it on an airplane, but fortunately have 2 510's to use.
<br />Would not recommend this item.