The E♭ Locrian scale has 7 notes: E♭ – F♭ – G♭ – A♭ – B𝄫 – C♭ – D♭. Locrian is the darkest mode: a minor scale with a ♭2 and a ♭5, built on the 7th note of the major scale. Its root chord is diminished, so it is used for tension rather than as a home key.
E♭ and D♯ are the same pitch, so this page covers both names; the notes are spelled from E♭, the way the key is usually written (a double sharp or flat is the correct spelling for that degree). Compared with the E♭ major scale it has ♭2 (F♭ instead of F), ♭3 (G♭ instead of G), ♭5 (B𝄫 instead of B♭), ♭6 (C♭ instead of C), ♭7 (D♭ instead of D).
The explorer above is set to E♭ Locrian: the whole neck is mapped, and you can zoom into any of its 7 positions, change the labels to degrees or fingers, and hear it up, down and in patterns.