Wooden Camera Extra Stage Set for UMB-1 Universal Matte Box

This extension works as expected. One thing to note is that with only 2 stages and the mattebox rolled back, you still have access to the swing away release pin. With a 3rd stage and the mattebox rolled back, the pin is covered so you'll need to always roll the mattebox forward in order to have access to the pin. That's not a big deal at all but something to be aware of. Otherwise, this 3rd stage works like the others and it's brilliant. I love the tray catch functionality. The front-most stage is a little tighter but that might be because of the way I installed it. Again, not a big deal. Really awesome mattebox and the filters/stages work well. I love that the trays accept 4x4 filters AND 4x5.65 filters. The 4x4 filters stay in place and hold well. If you're using 100mm filters (2mm thick instead of 4mm thick), you'll have to modify them as the filter trays won't hold them. The filters will be too small. Again, not a big deal, as this mattebox was meant to be used with 4x4 and 4x5.65 filters so if you stick to that, it works REALLY well.