Springfield Marine 9" Non Locking Base For Spring Lock/Clip Lock Posts. It features high-strength aluminum with a satin finish and an 8" hole pattern. The mount requires a 4" hole below the deck for installation. Use with any Non-Locking Spring-Lock or Clip-Lock Post (sold separately). Features of Springfield Marine 1640002 9" Non Locking Base For Spring Lock/Clip Lock Posts 8" hole pattern High strength aluminum construction Below the deck mount (requires a 4" hole in deck) Use with any locking Spring-Lock or Clip-Lock Post (sold separately) Finish: Satin Package Contents: Springfield Marine 1640002 9" Non Locking Base For Spring Lock/Clip Lock Posts Springfield Marine 1640002: 9" Non Locking Base For Spring Lock/Clip Lock Posts