A pair of compression bands of the patellar tendon, curved to fit the shape of the ball, just place it right below to take advantage of protection against vibration, shocks and beatings with the integrated upholstery ; making it allied solid for sports, crafts and other hobbies that require stability and comfort of the patella or a relief in case of tendinitis for example. The implementation of these bands is easy but you have to scratch the Velcro so they do not move. Good point: the movements are not hampered. An excellent compromise between the small and the great band toggle maintenance, at an unbeatable price.