This is the French Model 1886 Lebel Infantry Bayonet made for the various WWI era - possibly WWII era - "Lebel" and "Fusil" Infantry Rifles, with evolutionary modifications. Most of these were used by France or French-controlled colonies and regions.
Most of these are not uniquely marked; however, this particular example bayonet (image below) is unique in that it is clearly marked "USSR". I was not aware of any of these being used by the USSR; however, it is known that some of these types were used by Poland.

Overall length - in scabbard - is ~25-1/2";

Hilt is ~4-5/8" in length (including crossguard), ~2" at widest point (crossguard); solid brass grip; cross-guard and latching mechanism are integrated together. The handle - or grip - is held in place by a screw-nut and is removeable. The original Model 1886 was a silver-alloy handle (this one is brass) with a hooked cross-guard lower quillon (now arsenal removed, or newly manufactured without).

This blade is nothing more than a pig-sticker. It is a straight 4-edged-blade (cruciform) and is ~20-1/2" long, ~1/2" wide at ricasso, 4 full-length fullers.
No blade markings are apparent on this example.

Scabbard is ~21" in length; tubular steel with ball-finial.

Below is an unusual marked variant of this type Lebel bayonet; this is not a normal marking. Seems odd this is in English marked USSR and not Cyrillic and CCCP. Perhaps it was a capture piece and the location noted.