What's a TDBU (Top-Down-Bottom-Up) Shade? 

Its a shade that you can open from the top or bottom; have it raised completely, have it completely closed to cover the window, or anywhere in between.

** All of these are Health Canada Approved **

https://www.canada.ca/en/health-canada/services/home-safety/blind-cord-safety.html

These three pictures are the same TDBU shades - set in different positions. Each shade can do all positions. These are cordless, move the middle bar to the position you want, then move the bottom bar to the position you want.