Springfield Taper-Lock 9" - Aluminum - Round Base [1600003]Taper Lock 9" Aluminum Round Base Features: 9 Round Base With 8 Hole Pattern High Strength Aluminum To Withstand All Conditions Below The Deck Mount Requires A 3 1 2 Hole In Deck Use With Any Taper Lock Post (sold separately) WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings. ca. gov.