Backyard Expressions 4Pcs Offset Umbrella Base Water&Sand Filled Umbrella Base for Cantilever Offset Patio Umbrella

STURDY 4-PLATE DESIGN: Made with interconnecting pins to lock your umbrella base in place and secure it for hours of enjoyment. Rugged & WEATHER-RESISTANT: Made of HDPE plastic and treated with weather-resistant coating, waterproof, stable and durable EXCELLENT STABILITY: These plates can hold up to 15 liters of water (per plate) or 50 pounds of sand (per plate), ensuring that your patio umbrella can remain upright in high winds EASY-TO-FILL SPOUTS: Each board is equipped with a filling port and a screw cap, which can be quickly filled and filled BASIC PARAMETERS: suitable for all kinds of cantilever patio umbrellas (excluding the crossbar base). Overall dimensions (per board): 19.7" (length) x 19.7" (width) x 3" (height); capacity (each board)