I enjoy my Chus. In fact I'm listening to them right now. They are my default wandering around IEMs

I haven't verified, but what it should do is convert the volume level from logarithmic to linear. I'll explain.

Log based systems in effect take the logarithm of value. This means that if the volume goes up 10x there is still room on the scale.

Linear doubles the sound when the number doubles (2 doubles to 4, 50 doubles to 100).

In specific cases you can find things happening like with a lot scale 1 can be too high. But with a linear scale that same 1 value usually ends up somewhere around 5-10. The downside is that if you have a device that requires the upper end of scale you've lost all volume control, it has become just an on-off switch as the granularity at the top is lost.