Gravipod 14" Round Umbrella Base Weight Bag - Up to 50#. Safety solution for Patio, Offset and Cantilever Umbrellas. Heavy Duty Ballistic Polyester. Weather/UV resistant New! 14" Round design - simple and convenient - Just add your own sand* Designed for base sizes of up to 3.0" - 3.5" Rugged and durable Ballistic Rip-stop polyester with PVC lining and triple stitch-locked seams. Adds up to 50 lbs of ballast to your existing umbrella stand, based on amount of sand added Soft and easy on the toes, no hard edges to kick. No rust, dings or dents.