Spring Activated Steel Ledge (Supports Open Umbrella) - 1.3 mm Aluminum Pole (Manual Lift Frame) - 1 3/8 Inches Diameter Upper Aluminum Pole - 1 1/2 Inches Diameter Lower Attachment Pole - 5.0 mm Chrome Plated Steel Ribs - Stainless Steel Joints & Rivets - Silver Anodized Centerpole - Galvanized Steel Notch - Non-Twisting End Tips - Metal Bell Cap