I bought this product by W&N as well as Universal Spray Fixative HC10 by Sennelier at the same time to test them both. They are both excellent fixatives for pencil artwork on paper. They both have a strong toxic smell; this one may have been a tad less deadly than the other one, but still, use outdoors and don't inhale.
After only a single light coat (3-4 seconds on a 9x12 inch drawing from about one foot from paper surface), this fixative sealed my drawing almost completely with only a bit of graphite rubbing off; but even then, it smudged way less than it did without any fixative. After a second light coat, the drawing was very well fixed.
I do recommend this product, but I feel the Universal Spray Fixative HC10 was a bit stronger with the same amount of spray.