PO 3.5x21P is a modern optic produced by BelOMO -- Belorusskoe Optiko-Mechanichesckoye Obyedinenie (Belarus Optical & Mechanical Enterprise) in Minsk, Belarus. It is designed to be similar to the ACOG but with a breath-takingly wide  wide field of view that so far no other Russian optic has matched.


Optical clarity is extremely high and in my opinion is one of the brightest and clearest optics I've used...the image quality is very impressive. It is also one of the easiest scopes to zero due to the reticule design. Like many Russian scopes, the PO 3.5 has a 1.5m range finder for estimating distance to a standard height target but uncommonly it also has a 0.5m scale for prone targets as well. The PO 3.5 has not been adopted by the Russian or Belarus armed forces. While this is probably the heaviest optic I've used  at 2.2lbs (outside of the NSPU of course, 5lbs), the weight penalty is somewhat offset by the amazing field of view and the high glass quality.

The PO comes in a few versions - illuminated and non illuminated models as well as a variety of caliber specific types. Like many of the modern Russian and BelOMO designed optics PO 3.5 has no turrets to adjust for elevation or windage, the intent is to zero the weapon based on the 400m concept and then use the additional range chevrons for longer distances if necessary. There is no need to adjust anything when shooting, the rifleman only has to aim COM out to 400m and will have a reasonable chance to hit.

PO3.5x21P Saiga 7.62x39, PO 3.5x21P and PO 3.5x21P2

The PO 3.5 is zeroed on the 400m concept and is probably the easiest of all the 5.45 scopes because of the design of the reticule. Instead of having to adjust point of impact to be approximately 22cm higher than point of aim, the PO has this distance built in to the reticule itself. All the shooter needs to do is align POI with POA by using the boresight cross at the top of the reticule. After confirming that the boresight cross is indeed where the rounds are landing at 100m, the shooter then uses the large chevron for center of mass aiming out to 400m. There are additional range lines for 700, 800, 900 and 1000m.

 

 

PO 3.5x21P is battery illuminated like many of the older PSO style illuminated optics. (CR123 type)

 

 
Alternate reticule (courtesy Miglan-20)

On the SGL31

For 7.62x39 if point of impact is 23cm higher than point of aim at 100m the trajectory will coincide at 300m. This is the same height of the boresight cross over the chevron at 100m, so if POA = POI with the boresight cross, using the chevron will adjust for the proper 300m zero.

PO 3.5x21P2 Saiga 5.45x39
42.8 ounces with NPZ mount, 34.4 without
2x AA batteries (Not CR123 like regular PO 3.5)

Battery compartment is very different than any Russian optic I've seen, takes 2 AA batteries and has variable intensity rather than on/off

Elevation (arrows are reversed from PSO type optics):
ВВЕРХ = Counter clockwise = Trajectory Up
ВНИЗ = Clockwise = Trajectory Down

P2 windage adjustment (arrows are reversed from PSO type optics):
ВПРАВО = Counterclockwise = Trajectory Right
ВАЕВО = Clockwise = Trajectory Left

Interestingly PO 3.5 will cowitness with a T-1 style red dot when mounted to the Stormwerkz topcover on an AKSU rifle. This was not intended by any of the designers but it does work.