Patio Umbrella Deck Mount Dock Holder D2 3/8"Solid & Secure Deck Umbrella Mount bolt down umbrella base Perfect for Windy Days! Tired of your patio umbrella tipping over or wobbling in the wind? The Patio Umbrella Deck Mount Dock Holder is the heavy duty solution you need! Designed for permanent stability, this rugged metal base features 4 predrilled holes for easy anchoring to your wood deck, dock, or concrete surface, keeping your umbrella firmly in place, no more chasing after it on breezy