This is the Cover plate for TS 55, part #491750, it is to inrpove dust collection. I picked this up to use when I want to trim the length of a door in clients home. The TS55 hooked up to a vac, collects about 85% of the dust without the cover and about 90% with it, not a huge difference, but I'll take all I can get.

To install the cover, first remove the Splinterguard.

Next, attach the mounting bracket with the thumb screw.

Slide the cover into the slot in the saw.

Tighten thumb screw.

Here it is installed, you can see the hole that allows you to get to the screw to remove the blade is now covered. As I said, this is not a "knock your socks off" improvement, I do however find it to be a worth while product.