Dickies Men's Tradebuilt Duck Canvas Double-Knee Carpenter Pant

What does the double knee actually do?

Extended double-layer panels over the knee, where duck canvas wears through first if you're kneeling on concrete, decking, or roofing. The panels are cut long, so coverage holds whether you're upright or down on your knees.

Do they take knee pads?

The double knee panels are reinforcement layers — sources don't list internal knee pad pockets on this style. If you need pad inserts, verify against the Dickies spec sheet before ordering.