Is this plant substrate legit?

Found this nutrient soil at a really cheap prize but can't find any info on it online. Anyone knows if this is legit? I don't expect it to be as good as the more expensive brands, but if it's better than nothing.. I'm planning on placing it beneath the sand.

This is what it says in the description: "Nutrient soil is a bottom cover with a compact structure, which acts as a growing substrate for certain aquarium plants. Due to the dense structure, catfish and algae eaters will also feel at home here, as it is a good bottom to dig in."

Members (if any) who have used this product can comment specifically. I will just mention that I have found these so-called plant substrates to be more trouble than benefit. Fish can be affected, and plant growth is often no better, so it becomes an expensive waste.