Take the appropriate measures.

Heights.
  (1) For large dogs place arm in top position and read height measurementon the yellow scale.
   
(2) For smaller dogs, turn the rod and place the arm in the middleposition and read the height off the black scale.
Breast and length.
  (3) Measure breast and lengt. The arms are mounted on the topand middle position and read off the blue scale.
  (4) Length measurement (optional). Arms are in top and bottom positions. Length is read off the red scale.