What is ך?

ך, in Hebrew, is the final form of the letter Kaf. It represents the sound /χ/ (voiceless uvular fricative) or /k/ (voiceless velar stop) depending on the pronunciation (Ashkenazi or Sephardi/Modern Hebrew, respectively). The final Kaf (ך) only appears at the end of words. It is one of the five Hebrew letters that have a different form when appearing at the end of a word; the others are Mem, Nun, Pe, and Tzadi. Its Gematria value is 20, just like regular Kaf.