Solid, takes good filters (based on my purchase of the same brand filters, I could not judge on other brands but see the system I think it is no problem) remember not to buy a bigger ring to fit your goals and Ø reducing rings to mount them in your lower Ø objectives (eg if you have 3 targets a 50 mm, 58 mm and a 77 mm: take the ring adapter from 85 mm to 77 mm filters and buy the reducing rings 77 mm to 58 mm and 77 mm to 50 mm adapter rings worth as a dozen each then the reducing rings are worth 3 parts and these will be used to Screw all accessories that can be purchased thereafter, even your caps-protected targets will have a single Ø 77 mm) For graduated filters take rectangular 85 mm x 110 mm (it allows to play more on the height) and for taking long expos squares I bought filters: Formatt Hitech Neutral Density Filter Kit soft Gradient Edge 85 x 110 mm and: Formatt long exposure Hitech Filter Stops Prostop 3.0 10 85 x 85 mm
