The WBS RealStop© is the real Double-Stop and has got nothing in common with the regular build-in so called Feelstop that most of the steelguitar builders use.
A Feel- or Double-Stop is used to detune one String with one Kneepedal to more than one Notes. For example a Feel- or Double-Stop is used on the second String on most E9 tunings to detune the Eb to D and C#. With a Feel-Stop - as I used to call them - the stop for the Tone D is hard to catch wich means you are usally to low and results in a wired and wrong chord or keychange.
The WBS RealStop©, optional available elaborate and build-in a special box, eliminates that abuse finally. You never have to look for the inbetween-tone. Elaborate but the perfect solution for that pain in the ....