d6f7415d_200G_and_needed_modifications___What_it_s_good_for_
[Feature] Focus [ECP] Electro Static [Ampro] Electro Magnetic [What it's good for.] 
EM focus allows tighter focus than ES and it is ajustable for different parts of the image.
The Ampro Esprit 4200G and needed modifications.
What it's good for.