Z GT-320CD (Suede): 320mm Classic D-Shape / Full Suede / Optimal Legroom / Heritage GT Style Z GT-320CD (Leather): 320mm Classic D-Shape / Premium Leather / Ergonomic Flat-bottom / Versatile Z GT-320MS (Suede): 320mm Modern GT Square / High-Grip Suede / Aero-Design / Tactical Control Z GT-320MS (Leather): 320mm Modern GT Square / Fine-Grain Leather / Modern Profile / Pro Racing Z GT-300MC (Rubber): 300mm Modern Open-Top / Injection Rubber / Max Durability / Ultimate Utility ZGT-300MC (Suede): 300mm Modern Open-Top / Pro Suede / Unobstructed Dash View / Formula Style