The odds of unboxing a StatTrak Factory New knife with a particularly low float value in CS2 are extremely low, combining several layers of rarity:

Base Knife Drop Rate: The chances of getting a knife from a case are around 0.26%, or roughly 1 in 385 cases.

StatTrak Rarity: StatTrak items are 10 times rarer than their non-StatTrak counterparts. Therefore, the chance of a knife being StatTrak is approximately 0.026%, or roughly 1 in 3850.

Factory New Condition: Factory New is the rarest wear level, with only about 3% of skins dropping in this condition.

Low Float Value: Within the Factory New range (0.00-0.07), a "low float" implies a float value closer to 0.00, which is even rarer. The probability of getting a specific low float value is not publicly disclosed, but it's significantly lower than the general Factory New drop rate.


Combining these factors

Multiplying these probabilities together (approx. 0.026% * 3% * "very low float probability") results in a minuscule combined chance. It's difficult to give a precise number due to the unknown low float probability, but the odds are extremely low, likely in the realm of 1 in several million or more.
In conclusion, while it's technically possible to unbox a StatTrak Factory New low float knife, the chances are exceptionally slim, making it an extremely rare and valuable outcome.