Compatible Pole Diameter: Designed with dual-size couplers (1.5/38 mm and 1.9/48 mm), the adjustable outdoor umbrella table easily accommodates patio umbrella poles ranging from 1.5-1.9/38-48 mm in diameter or smaller. The integrated tightening knob ensures a secure and tailored fit every time. Weatherproof HDPE Structure: Made from tough HDPE material, this umbrella table tray is completely waterproof, resistant to fading, and will not crack from outdoor exposure. Additionally, cleanup is effortless with a quick wipe.