I am new to the FOG. I have been watching many videos about using the Festoons. I recently purchased a TSC55, MFT# table and dust extractor. I have noticed when I start cutting, dust comes out of the viewing port. In a video, can't remember which one, I saw a TSC 55 equipped with an attachment that I did not recognize. It looked like a Festool part. It screwed on where the splinter guard attaches and was Festool green. It looked like it better covered the opening. Any ideas? Thanks