A cast iron umbrella base: a round plate 19.5 inches across with a dual-purpose stem that adapts to different mounting setups, standing 20.5 inches to the top. The round profile keeps it low and walk-around, which matters on a busy dining floor where a square base becomes a trip hazard. It anchors a freestanding umbrella wherever shade has to stand independent of the tables themselves. It is not compatible with every pole in the range, so send us the umbrella model along with the order.