The design
One seam, running around the back of the knee.
Every sleeve in the range is built on a spiral seam that wraps behind the joint rather than sitting flat across it. The shape is what lets the sleeve hold uncompromising compression over the knee without a seam fighting the bend.
The neoprene is specified to endure the demands of the sport: it keeps contact through the full range of motion and insulates the joint, muscles, tendons and ligaments. Thickness and density change between the three sleeves. The construction does not.
All three are made to the same standards in the United Kingdom, carry an antimicrobial inner liner, and are approved for IPF competition.