Skipping some of the evolution and variations, basically there are two version.
One is a large folder designed for Military use called the "ES1-M" (Emerson SEAL (model) 1 - Military). All ES1-Ms are customs and as such, demand high secondary market prices.
The other is a slightly smaller version for the commercial market called the "Commander". The Commander is a production knife manufactured by
EKI. For more information of variations on the Commander, you can check
here.
The ES1-M is about 20% larger overall.
Pic All ES1-Ms I have seen are chisel ground.
Pic
Both knives have the same features, including a recurved blade and the "wave". The wave being a feature that allows for the opening of the knife as it is being drawn. Absolutely the fastest opening knives on the market.
More pictures and information can be found on the
Gallery.
Hope that helps
John
[This message has been edited by John Hollister (edited 10-30-2000).]