Two receiver diameters, 2" and 1.5", are built into the same 9.5" tube, so this stand takes more pole sizes than a single-socket base. Water or sand goes in through a 1.5" injection hole to a maximum of 36 lbs of water or 54 lbs of sand. Four casters, two of them lockable, and built-in handles make an empty 6.5 lb base easy to move and a filled one easy to hold in position. High-strength PE with a concave bottom keeps the surface rigid. Overall 17.5" x 17" x 15.5".