The most common type of flagpole installation is the in-ground foundation sleeve method which calls for 1 in. of the flagpole to be encased in the ground sleeve for each 10ft. of exposed flagpole height. The diameter of the sleeve should be al least 2 in. greater than the outside diameter of the flagpole with the area between the flagpole and the sleeve filled with dry sand. Sleeves with a 6 in. diameter are supplied with a base plate and grounding spike. Sleeves with a diameter greater than 6 in. are supplied with a base plate, support plate, grounding spike and, for ease of vertical alignment, steel centering wedges welded to the inside of the base plate.Additional Shipping Costs are required for these items. They are shipped by Commercial Carrier or Truck Freight only. Customer service will calculate the shipping cost on this item and contact you by email for your approval prior to fulfilling your order.