Swivel seat mount ?

Attwood Clamp-On Boat Seat Swivel

2 - Boat Wise Swivel Seat Mount 12 Way Locking Position Marine

Garelick Boat Swivel Seat Pedestal

Wide Application: The seat turntable can be easily installed in various large vehicles, including RVs, commercial vehicles, and engineering vehicles,

Swivel Seat Mounting Plate, Universal Swivel Seat Base For High Load Commercial Vehicle

Brocraft Boat Seat Swivel Mount Removable Bracket Seat with Quick Disconnect

Osculati Pedestal with swivel seat mount grey coated aluminium 457

T-H Marine Seat Swivel

7 Boat Seat Swivel

Springfield Marine® 1640202 - Spring-Lock™ 7 L x 7 W E-Coat

Swivl-Eze 238 Series Seat Mount, Forward Handle, 3-Degree Angle, Plated Steel 238153-1 - The Home Depot

SeaLux Universal Heavy Duty 360 degree 7 to 8-3/4 Seat Swivel

Swivel Seat Kit with mount