I use a Chrosziel compact 16:9 mattebox and love it. It pretty much lives on the camera fulltime.
The filter trays and mechanical parts are aluminium and the box/shade is a fibreglass material. Their standard mattebox has two filter trays, one that rotates and a fixed one. They also come with a french flag.
If you have internal focus lenses I would recommend a clamp on box rather than one with rails. The rails can be annoying when shooting off the shoulder, add a fraction more weight and really arent needed.
Be very careful in who uses it. They are not really designed for hard news use. If its used by someone who treats it like their own there will be no problem. Give it to anyone else and you might have problems.
You also need to bear in mind the cost of the filters. As dinosaur said, they start at around $100 depending on the type, quality, and brand. Expect to pay around $200 or so for a diffuser or colour grad made of quality glass. There are cheaper resin filters around but save yourself the bother and go for the better glass ones. There is a huge difference in quality.
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