This 4-in-1 modular umbrella base features four interlocking plates forming a 38.58"" x 38.58"" base for 10-15 ft cantilever umbrellas. It holds up to 330 lbs when filled with water, sand, or a combination, providing excellent wind-resistant stability. Made of high-density polyethylene (Hdpe), it resists Uv, moisture, and cracking for long-term outdoor use without fading. Four large fill ports on each plate allow quick filling or emptying, with no tools needed for assembly or disassembly. Compatible with most cantilever umbrellas with a cross base shorter than 35.5 inches. Perfect for patios, decks, gardens, and poolside areas seeking durable, stable, and easy-to-use umbrella support.