Almost ALL DYI Rolling Shelves are 22" deep. The WIDTH is cut by you to fit the opening. Kits are usually MAXIMUM 24" wide. Example: If you have a Frame Opening of 21" , Then you need a 20" wide finished Drawer. (you cut it 1" less to allow for both 1/2" thick side tracks)
I’m not sure what the question is. Contact them to get, if you feel you need it, or include in the review. I felt directions were unnecessary. There’s a left and right glide system. They need to be screwed into a floor. They need to be on the same plane and equal distance front and back. A paper layout would have been nice but I was able to just measure and place and screw in. That said, I was disgruntled when I didn’t receive the correct number of screws so it would be appropriate to identify, in a review, that their packaging process is custom every time and flawed.
You MUST cut the drawer WIDTH 1" less than the FRAME opening. This allows for both 1/2" side tracks