Kobra comes in many
different versions as it has evolved over the years.
While neither a pure red dot or a collimator sight,
Kobra is unique in that it has 4 different reticule
patterns that can be quickly accessed by pressing a
button on the side of the optic.
In the US Kobra has somewhat of a checkered
history due to a few QC incidents with certain batches
of imports that had defective on/off switches, but
Kobra is well liked by Russian troops and it has
proven itself in combat under harsh conditions in the
Chechen conflicts. Currently manufactured by Axion,
Kobra has not been formally issued a GRAU index number
and is not officially in service in the Russian
military. Despite that it has indeed been purchased
privately by individuals and used in a variety of
Battery life is extraordinary at approximately 800 hours using Ni-MH rechargeables rated at 2300mAH (according to one owners test described here on AR15.com). The optic is center over the bore and weighs 15.1 oz.
Kobra has also been copied by Chinese airsoft companies and this has led to a certain amount of confusion and uncertainty regarding what versions are real and which ones are not. To my knowledge only one older version of Kobra was copied and it is relatively easy to tell the difference (See pictures further below).
It is often said that point of impact changes based on which reticule is selected, but it is probably more accurate to say that you can zero point of impact to either the dot or chevron. Zeroing on one but switching to another will show that the POI changes and this has led to a perception that the optic is somehow flawed, but actually it is intended for you to decide what reticule pattern to zero with based on your preference.
One example of how this could be useful is by zeroing to the dot at 100m but using the chevron for actual shooting. I haven't tested this yet but the difference in POI vs POA should approximate the AK74 400m zero.
Another factor would be that while the POI will obviously be different if using the 3 bar reticule, it appears to be designed for CQB and the rounds should land somewhere in the empty space between the 3 bars. While obviously not as precise as the chevron this shouldn't matter for room clearing distances.
You can see with Kobra that you have the ability
to change reticules for different scenarios...large
three bar reticule for CQB, small dot for more precise
shooting and a combination of either chevron and dot
or just chevron as needed for general use. I am not
aware of any other 'combloc' optic that has these
features. (Nearly developed PK06
is similar to Kobra)
Rare military version of EKP-8-02 with sunshade. The
shade is plastic and not rubber like the EKP-1S-03M
EKP-1S-03M, EKP-8-02 and EKP-8-18 Weaver mount (borrowed from Avtomats-In-Action)
EKP-1S-03M and EKP-8-02 comparison
There is only one fake version of the Kobra but there are about 5 non fake versions on the market. Most Kobra's in the US are legit and there is little risk of buying a fake, but it pays to know the difference between the one airsoft copy and the rest of the legit models.
Something to know about the airsoft fake is that it was faithfully copied from a real Kobra, but that specific version of Kobra is extremely rare in the USA. I have only seen one or two for sale personally, compared to hundreds of the common version EKP-1S-03M.
These pictures compare the fake to the most common version over here which is EKP-1S-03M - basically the model that came after the airsoft fake was created.
Keep in mind that there are a few real Kobra's in the US that the fakes are based on, however you can tell the difference primarily by the brass mounting hardware similar to the pictures of the real Kobra.
You should still be able to tell the difference by the screws and brass fittings on the clamp
Models with blue writing on the side are rare but not fakes. They are simply older versions of the Kobra that came to the US a long time but there is no reason or evidence to believe they are faked. Model designation is also EKP-1S-03 but there are significant differences in body design and construction than the faked EKP-1S-03.
I apologize for not giving credit to the original creator of these pictures, I have not been able to locate the author's name. Many thanks however... they have been invaluable in helping people determine what they were buying.