Aluminum shells ship without sand to minimize freight costs
Thru holes are provided on the sleeve for securing the umbrella to the stand with a restraint pin or bolt - see pdf file
Sleeve is welded to round plate that secures underneath the base to prevent the sleeve from pulling out of the shell. see pdf file
Thick durable feet made of Polypropylene provide protection against surface scratches and keeps base plate off of the ground, minimizing moisture buildup
Wheels are standard on the 2 larger bases
Standard finishes: Black, White, Almond, or Brushed Aluminum
Click Here for .pdf file with Design Features and Model #'s