Hi to all, got the same problem also. returned to cathay for an exchange to another item.
Five of the sales staff have fun that afternoon trying to fix the newer version that mark clearly "OM-EX for the Canon 420EX and Nikon SB600", but without luck. Becareful, try before buying this OM-EX, ok!
Nikonians forum also got this problem.
Well, me was confuse and decided to write to this company and there this is:
First reply email;
Please calm down and answer just one question. Did the unit you purchased
say for the Canon 420EX and Nikon SB600, as this is the NEW Version of the
OM-EX that fits both units nicely per our instructions in this packaging. If
it ONLY said for Canon 420EX it is the Older unit that will ONLY fit the
Canon 420EX and indeed WILL NOT fit the Nikon SB600 flash at all.
And yes we do have the NEW OM-EX on our Nikon SB600 here in the office and
it fits and works just fine. So please as we said at the beginning just Calm
Down and try the unit intended for the SB600 and packaged as such. We have been supplying proper fitting units for over 25 years now with very few complaints such as yours.
Ernie
www.stofen.com
2nd reply email;
Just tried to clarify the model you purchased as we had made a change in the OM-EX to better fit the Canon 420EX several weeks before we even saw the Nikon SB600 flash. We then right away changed the package to reflect the SB600 as away of knowing which units were which. When the SB600 became available here we had one sent to us by overnight Air to see whatwe had in existing product that might fit and
found the New OM-EX to be a good march. It does, per our instructions, need
to be stretched by pulling apart on the long side before applying to the
flash. As you also must do the Canon 420EX flash as well. This is because
neither the Canon 420 or Nikon 600 flashes have anything to use on the flash
to hold on a unit, with out using something like Velcro, other than a
pressure fit with our Soft material Omni units. When the unit is slipped
onto the 600 head it will go all the way down on the top protruding side of
the flash head and about half way down on the opposite side. It fits this
way tight enough that you can pick up the flash just holding the Omni at the
top and not have the flash fall off, which is our company criteria for
attachment to any and all product we offer and have offered since 1979. We
have ALWAYS been and will continue to be an honest and respected company
that puts the customer and customer service first and foremost. Or we would
not have been around for 25+ years for sure.
Ernie
Conclusion of story is it still cant be fitted to SB600!