These are super cool knee pads! They fit well into the CAT pants and can stay for washing and drying in the machine. No damages so far. We have washed the pants about 5 times now.
The pads, depending on the size of your pants, and fit around your knees, when you kneel, you might need to make sure the pads are in a good position for you.
By the way, the CAT pants are fantastic as well! Totally recommend. My son loves his, all the way.