[1] The text deals with the Geulah (Era of eschatology and salvation) and describes its signs vis-a-vis an evaluation of a proposed 999 footsteps of the Moshiach's arrival.
Rabbi Kasher omitted the chapter on the confluences of Kabbalah and science called Sha'ar Be'er Sheva (Gate of The Seven Fields of Wisdom).
The B'nei Brak edition, which did contain this chapter, was out of print for over twenty years, thus making this "lost doctrine" of the GR"A [the Vilna Gaon] totally unnoticed by scholars and the public.
"[3]The text has become popularized amongst the adherents of Religious Zionism who perceive parallels between current and recent historical events and those forecast in the book.
He first wrote against Kol HaTor in a ten page pamphlet in the year following its publication in 1968 and later expanded upon the matter in his work Teshuvos VeHanhagos.