The Diamond Mini fountain pen now comes with Aluminum Parts!!
Piston filler type fountain pen.
The Diamond Mini is about 1 inch shorter than a full size Diamond 580 fountain pen.
A quick no brainer guide in choosing nib sizes in an overly complicated fountain pen world:
If you write small, go with an EF
For the normal writer, F is the most popular
If you tend to lean on a bigger font, M will be perfect
B is for statements!! Sign a check in B, write a header in B, do some coloring/shading in B