K&F makes quality photographic gear at a modest price, I have been happy with their products in the past and this filter is no different. It comes in a sturdy box and a plastic lens holder along with three lens cleaning cloth in hermetically sealed envelopes.
It easily screwed on to my beat-up Sony 24-105 G lens, it also stacked on to the UV filter. It feels well machined and has a knurled edge for an easy grip.
The effect is pleasant and slightly painterly. I don't feel comfortable uploading headshots of people, but it softens the highlights in portraits in a nice subtle way especially if there is strong rim light. 1/8th is a very subtle.
I would like to add that most of the time a blooming light source looks good, however if you have a subject in front of the bloom it can obscure the subject. You can see this a bit in the my photo with the house light behind the rock. The bloom is cool looking however if that had been a model it would blocked her.
I often add a glow or the variation called the Orton Effect in post. This black diffusion filter is cleaner in that it only affects the highlights. I tried the filter on a sunset shot and it had no change at all, may have to go to a 1/2 or a full diffusion to see any change.