Passionate amateur photographer, not a professional. Review given without having used the filter in real-world conditions. I reserve the right to modify my review.
Ordered and received 2 days later, so excellent.
The plastic case is designed for a single filter but manufactured for 11 different diameters, limiting production costs. Too big, made of plastic, and the closure is unreliable. It seems fragile and brittle over time and with repeated handling, so not ideal. The filter screws on easily, even with my large fingers. Good construction, decent threading. So, very good.
In my case, permanently mounted on K&F adapter rings from 62 to 77 mm. The 77 mm K&F filter, with its adapter rings, fits perfectly into another 72 mm Gobe metal housing. The whole assembly is held perfectly using just the Gobe lens foam. No other adjustments were needed. This filter will fit my 62, 72, and 77mm Olympus lenses in one easy step. The price is reasonable; other brands offer it for more than twice the price, so given my beginner level, I'll practice with this filter and see how it goes, or not, and perhaps buy a higher-performance model if needed.

Another advantage of the Gobe box, besides being a metal candy tin, is its much smaller diameter compared to the K&F plastic one.

It's missing the cleaning cloth, which is included with competitors, like Gobe, for products in the same price range. Oh dear.
All that remains is the testing and use in real-world conditions. And there, I hope the magic will happen... After storing it untouched, I take the filter out, and to my dismay, it's so dirty, like a car windshield, even though it hasn't been out of the filter case with the other filters I use more often. Huge disappointment. It looks like grease stains that can't be removed, even with lens solutions and other filters. So, straight to the bin.