The CopperJoint Knee Sleeve is made of a thin flexible material that is rated to be ant-microbial. I tested this sleeve extensively, I can not comment on whether or not the copper infusion makes a difference, it did remain comfortable and did provide great compression. Best of all it remained breathable and did not cause me to sweat. The silicon beads on the upper and lower portions prevented the sleeve from sliding up or down my knee, regardless of how much I moved around. Overall this sleeve did a great job at providing constant compression. If you are looking at this as an alternative to a brace, this is not for you, as a compression sleeve it works extremely well though.