A. The size from the middle of the toilet to the edge should not exceed 20 cm.
B. Distance between screw holes: 11 cm - 19 cm.
C. Distance between screw holes and shell: at least 3 cm.
D. Distance between screw holes and toilet seat edge: 5cm - 9cm
E. Distance between the centre of the bidet and the wall: at least 31 cm.