Slide the end of your tube through the tube key's slot until the end of your tube is just passed through.
Wrap your tube around your tube key (like swaddling a baby, or making a burrito) while gently pressing the tube against the sides of the tube key slot until all of the tube's product has been pushed to the tube's opening.
This little key might not be strictly necessary to get everything out, but it IS handy and easier than cutting open the metal tube to scrape out everything leftover and cutting your hand on the metal edges....not speaking from experience or anything...
Very easy to use for the tube I am using easy to squeeze and get all the faded cream to the last bit.
Works like a charm!
Worth getting the main squeeze to access all the serum in the tube. Very efficient and easy to use!