Edit:
Updated with newer red dots and collimators, also clarified some details on the PK01 series.
(Also keep in mind this isn't every single combloc red dot manufactured, but it is the majority of them I believe)
Traditional tube style red dots:
PK-A
Grey model with lower mount (my personal favorite of the PKA family)
PK-A
Black model with high mount
PK-A
Weaver
PK02/PK23
Mine was marked PK02 but the common name is PK23. Has a flickering red dot that is easy to acquire and naturally draws your eye to it.
(In RS Regulate's 30mm tube mount, good stuff)
PK01 Series
The PK01 series is extensive and covers probably 8-10 models, maybe more. I'm still in the process of trying to nail all these down, I think I have 4 or 5 more to go (not counting the newest ones from BelOMO that we can't get). The hard part is knowing exactly how similar they are in construction...some of them clearly are in the same family, others just carry the ubiquitous PK01 designation. I'm still researching.
(Sorry, no pics for some of these, I don't have them in hand yet but they are on my list)
PK01 styles
Left to right VS, VM, V and Vi
PK01AA
http://www.eastwave.ca/products/scopes/pk01aa.html
Venezuelan PK-A
Venezuelan PK-A with older PK-A
PK01BT
http://www.eastwave.ca/products/scopes/pk01bb.html
PK01 from Eastwave's site, this one seems to be similar to the PK01 series that we're seeing lately (The PK01-Vi) but has some kind of automatic light sensor
PK01Vi
The body is marked PK01Vi but this seems to most commonly be called PK01VA or PK01VE or sometimes just PK01-V. A fair amount of confusion exists on it's designation... at different time periods and different vendors have used various names for it from what I have been told by Tantal. For simplicities sake I think I'm going to stick with what is written on the scope body and dispense with the designations that may or may not be based on mount types.
PK01Vi with the high mount (spacer above locking clamp)
With spacer removed
PK01-V
Is extremely low and will cowitness with rear sight on 1
Uncharacteristically for BelOMO optics it uses AAA batteries
PK01-VM
Super rare PK01-VS
Also extremely low and will cowitness on 1
Kobra EKP-1S-03M
This is not a collimator or a traditional red dot, however it has a proven reputation for toughness and is well regarded by Russian troops in Chechnya. There are a number of versions, this one is 03M. Currently produced by Axion, Kobra has had somewhat of a checkered past manufacturing-wise.
Collimater type optics:
Generally speaking the collimator optics are really non magnified scopes as opposed to tube style optics with dots. They tend to have a higher quality lense, less of a tube like field of view and gather more light for a brighter image than typical red dots. Latest versions like Obzor and Rakurs do not use batteries and are tritium illimunated, plus have some form of always on reticule like an regular scope would.
PK-AS
I believe this is sometimes called the S version and is generally what I think most of us are familiar with
Has an always on black oval and dot and uses batteries to illuminate the dot for low light shooting
PK-AS-V
Higher and center over the bore
PK-AS-W
Weaver
Rakurs
Has an always on German Post Reticule and uses tritium for low light shooting. 1P76 has entered service with Russian FSB units.
Russian marked 1P76 version without diopter
Rakurs-PM picatinny version
With PN16K nigh vision
Reticule
This is indeed a tritium illuminated reticule but because of the eye relief it's hard to get a decent picture of it. It's green and has a ghostly feel to it, I like it alot. No on/off, no batteries and nothing to worry about.
On the S12
SLR105
PK-AS-S and Rakurs, here you can see the relative difference in height
Semi top view, it was hard to get a good photo showing the height over the receiver. It does block the irons.
Obzor
Uses always on daylight reticule via the light sensors on the top and bottom and also tritium for low light shooting. Has a brightness filter to darken the FOV and make the reticule stand out more clearly.
Bottom and top light sensors for daylight reticule
Elevation and windage
Filter on/off (to reduce glare and bring out the contrast of the reticle better)
Daylight reticule
Tritium is similar…no triangle in the middle and the overall size is smaller, it fits in the empty space around the triangle. Tough to get a pic but hopefully you get the idea
Rakurs and Obzor
NIT-A
Always on German post reticule using light sensor technology like Obzor (it actually is the forerunner of Obzor). Also has filter switch like Obzor for better reticule clarity
Tritium illuminated but most likely will be too old to use or deactivated.
SLG31
With Obzor and Rakurs
NIT-A reticule
Shooting position from the bench
NIT light sensors
On the S12
More pics including magnified:
http//:russianoptics.net
Z