Review on Enhance Your Workouts With SKDK 7Mm Weightlifting Knee Sleeves For Men And Women - Boost Knee Support For Squats, Cross Training And More (2 Pack) by Rachel Murray

I'm a 6 foot tall male, my knee is 20" diameter at 4" above the patella. The instructions said to get a XXL, but frankly I think the XL would have been a better choice. They're fine though.These are neoprene, 7 mm thick. Neoprene doesn't breathe, so this is ideal for your 30-60 minute workout, not for all day wear, or for the long hikes or bike rides.Neoprene is a durable fabric that is stretchy, comfy, and offers a medium amount of support - not too loose, not too tight. And, it doesn't stretch out easily, and I have some neoprene items that have lasted a decade. However, the fabric is thicker than the thread, so if neoprene is going to fail, it's going to fail at the seams.These also aren't as long as other brands of knee braces I use - so if you're concerned about them slipping out of place, maybe get one that's longer.