Herr Berg of Dragunov.net has also graciously allowed me to link to his page on the Belorussian POSP. 

 I'm proud to say that I continue to use his site as a reference for many Russian optics and of course the SVD Dragunov rifle.

POSP on Dragunov.net

The most common version is the 4x24 but there are a huge number of POSP optics and a wide range of magnification options available - 4x24, 6x24, 6x42, 8x42 and more,  including some models that are variable power.

Most will have an SVD mount like the one shown below but there are quite a number that have the MTK83 AK mount as well. Probably the most useful for an AK is the 4x24V with Simonov reticule.

There are AK mounts and SVD mounts available. A few small versions are calibrated for 7.62x39 while the vast majority are calibrated for 7.62x54R. Some are also true mildot reticule POSP's. I am not aware of any POSP's (or PSO's) calibrated for 5.45x39 but there are probably more variants of the Belorussian POSP than any other Russian or former Soviet optic I've seen yet.

8x42 SVD Mount for PSL

8x42 with AK Mount

Example of POSP 4x24V with Simonov Reticule

A few things to remember:

POSP's are not technically Russian because while they were once part of the Soviet Union and in the US we still tend to think of them that way, after the breakup of the USSR they reverted to their official heritage. They are Belorussian, not Russian. Most are manufactured in Minsk at BelOMO from what I understand.

POSP's are not manufactured in the USA. There are a few brands coming onto the market in 2011 and 2012 that are being branded differently than the classic POSP's but those are simple brand names and logo changes only, they are still manufactured by BelOMO in Belarus like the rest of them.

There is some debate about the quality of POSP's vs NPZ PSO-1 and later type optics. I think it is safe to say that while some POSP's are clearly marked for civilian sales there is no doubt they are tough and well built optics that are built to high quality standards. I do not believe civilian POSP's would be considered milspec but for what the majority of civilians would use them for there is no doubt in my mind they will perform extremely well and as designed. 

I do not see anything that would make me assume POSP's are cheap or low quality optics. Glass is excellent especially for the price in USD, construction is solid and they tend to be free of factory defects in my experience.

I would not go so far as to say they are equal to PSO's from NPZ but I am hard pressed to see visible differences.