The Letter Khaph is one of the 5 letters which have a special letter which replaces it, when it is used at the end of a word
. The Khaph has a size of 3X3 kulmusim. The upper and lower corners of it's back should be clearly rounded, so that there is no confusion on whether it's a Beth or Khaph. The space in the middle of the Khaph should be exactly equal the width of the top and bottom lines, which is 1 kulmus.