Electronika Flanger FL01, features four control knobs (left to right) - filter, depth, speed and brightness. The rear panel sockets include (left to right) input, original(?), output, effect and power. On/off switch is designed rather for hand operation than for stomping. This device falls somewhere between stompbox and rack unit - no footswitch but it's obviously not rackmountable. I'd call this rare configuration "desktop". The unit is powered by 220V AC and sports a long power cord (see the lower picture). It also weighs much more than a usual stompbox because of the transformer inside.
Notice the "Sign of Quality" printed next to the effects' name - this nice logo was assigned only to high quality goods in the Soviet Union.

The FL01 was recently spotted on ebay with a $99 starting bid. The description says:
It is an old Soviet pedal - FLANGER. Has four controllers. The filter, depth, speed and brightness. A unique unique sound. The big opportunities. You Can make experiments! Important! Power 220 volt! The adapter is required.

Not sure you have to pay a hundred bucks for such big opportunities, but the unit might be cool as a collector's piece. The same Electronica plant made another flanger called PE-11 which is probably a successor of FL-01. PE-11 also lacks a footswitch and features the same controls (with english labeling).


Credits:
John, ruskeys.net
ebay seller: serg_rus77