A Half red & half blue (for N & S ) spray painted, with keepers.
Size
A . 25 x 15 x 10 mm
B.  37 x 15 x 10 mm
C.  50 x 15 x 10 mm
D.  50 x 15 x 10 mm
E . 75 x 15 x 10 mm
F . 100 x 15 x 10 mm
G. 150 x 15 x 10 mm

Ltekonline are the manufacturers of Bar Magnet Alnico used to demonstrate engineering principles in Engineering Colleges, Engineering Schools and Physics Lab Experiments for Engineering Teaching Lab in Universities