The opening for under the desk needs to go deeper and be wider most desk are open as wide as a chair but the lip on the mat doesn't go under the desk far enough for when you push you chair end when not at the desk and catches when you pull the chair back out. My heels catch on it as well when setting at the desk because it does not go under my feet at all.
All my chair mats are purchased from Staples. I find they are good quality and last a long time before replacement. I am in my office 6 days a week so the mat gets a lot of wear and tear. Love them!
This mat fits my needs exactly and the clerk was happy to order it for me . assuring me that if it wasn't what I wanted when I got it I could return it. I was very happy with that news.