. "In particular, air valves 36 and shoe insole 10, except for pad 40, can be integrally formed of relatively soft, flexible material, such as polyurethane, polypropylene, TR material or similar rubber-like material such as available from factories located in Montebelluna, Brescia, Vigevano, Porto San Elpidio (Italy), or similar flexible and impervious materials commonly used in athletic shoes and" . . .