I had been hesitating between several brands for a while to choose a filter holder for ND and GND filters. I took advantage of a flash sale to acquire this kit. I am not disappointed.
the set seems robust and easy to store.
The case, quite pretty, has 5 compartments, 3 of which, for square ND filters, can be lifted by means of a ribbon. On the back of the case, there is a ring to pass a strap and a passage for a belt. I would have liked a slightly more spacious compartment to house the adapter rings with the CPL filter when it is disassembled.
The assembly (or disassembly) of the elements is well explained in a manual in several languages, including French.

Main positives:
No color cast or loss of sharpness on the first tests carried out.
The plastic frame with its tabs to handle the ND filters.
The CPL filter installation system on the filter holder.
the knurled knob for mounting the adapter ring and the rotating block of the filter holder.
The very accessible wheel to control the polarizing filter.
Firm hold of the square filter on the filter holder.
The robustness of the metal filter holder.

If you have to find some negative points:
The slightly too vigorous maintenance of the square filter in the filter holder.
the click too hard to lock the CPL filter in the filter holder.
No pouch to independently protect the CPL filter in the case.
No CPL protective cover when the assembly is installed on the lens.