It is the bumper that stops the slide when the drawer is pushed in. This is from Sligh Furniture office furniture. I found a picture of a similar item from your website in black on the internet.
Bob from SWISCO responded:
October 19, 2020
Thanks for writing. Unfortunately, we don't have this exact drawer stop, but see if you could use something like our screw-on stop 32-125, or even the 10-112 . Take a look and let us know if you have any other questions.