Double-lock design：comes with 2 hand knob tightening screws to hold the umbrella pole securely, easily fix or detach the umbrella with a simple turn of the knob Durable material：made of high-density resin and anti-rust steel pipe for all weather resistant and sun protection Universal function: adjustable holder to fit 1.3"(32mm), 1.5" (38mm) and 1.9"(48mm) diameter poles, suits 7-11 feet market parasol umbrellas Multi-scenario use: applying for many leisure scenes like patio, deck, yard, garden, porch, balcony, swimming pool, lawn, outdoor cafe, restaurant, etc Efficient installation: easy to assemble, detailed manual instruction was provided, this classic product will make your outdoor spaces more attractive Helios&Hestia 26 lb Heavy Duty Umbrella Base, Square Resin Patio Stand Weight for Outdoor Market Table Umbrella, Black