Peak Enlarging Focuser. A very sharp grain focuser made by Tohkai Sangyo Ltd. Japan. Prof. Z. Koana System. Widely considered the best made. This one has minor scratches on the front surface mirror which do not affect the use. This will allow you to focus in the corners as well as in the center. For the perfectionist. This was Amelia's favorite. $150.
Microsight 3 Grain focuser by Bestwell Optical, Merrick NY. This was my favorite. $50 Very sharp and quick to use.