Space saving: lightweight and easy to move, providing good shade without taking up floor space Flexible design: fits all kinds of market umbrellas and cantilever offset umbrellas with 1.3"(32mm), 1.5" (38mm) and 1.9"(48mm) pole diameter, can be securely fixed to the flat surface of any standard railing Durable material: heavy duty steel construction in black frosted texture powder-coated finish, adopting stainless steel screws, anti-corrosion and anti-rust Multi-scenario use: suitable for clipping to railings on patios, courtyards, balconies, decks, house porches, docks, ships, fences, terraces, pools etc Efficient installation: easy to assemble,detailed manual instruction was provided Helios&Hestia 2PCS Outdoor Patio Market Umbrella Holder Clamp, Heavy Duty Adjustable Umbrella Base Stand Mount Bracket for Deck Railing, Courtyard, Balcony, Fence