Fixed seat pedestal with swivel.
Per the manufacturer, this pedestal measures 12-1/2″; we measure it to be approximately 13-1/2″ H x 9″ Dia. overall. The pedestal base mounts via (6) 1/4″ Dia. holes set apart approximately 4″ center to center.
Features 6-5/8″ x 6-5/8″ swivel head that hosts a custom 5-1/4″ x 5-1/4″ slotted mounting pattern.
The manufacturer has rated this pedestal AN: Not to be used for the helm/driver seat.
Material : Anodized Aluminum.
Dimensions : 12-1/2″.
Overall Dimensions : 13-1/2″ H x 9″ Dia.
Mounts :  (6) 1/4″ Dia. Holes Set Apart 4″ Center to Center.
Mounting Pattern :  5-1/4″ x 5-1/4″ Slotted.

Fixed Seat Pedestal with Swivel