✅This heavy-duty umbrella base features a round base design with two hand-turn tightening knobs for a secure, wobble-free hold on your umbrella. The double lock system (inner hole + outer knob) ensures a tight grip on poles sized Φ1.5" (38mm) or Φ1.9" (48mm), while plastic inserts protect against scratches. Made from rust-proof HDPE material and reinforced with a steel pipe, it resists corrosion and harsh weather, offering durable, all-weather performance. Its elegant, line-style black design blends seamlessly with any decor-perfect for balcony, yard, or poolside use. With a 68lbs weight capacity (when filled with water/sand), this anti-tip umbrella stand keeps your shade stable. (Note: Sand/water not included.) Ideal for patio, garden, or commercial setups, it's a sturdy, stylish solution for securing large umbrellas.