Boat Seat swivel is designed for permanent seat attachment.

Black finished, Heavy duty powder coated steel

Swivels 360-degrees ball bearing

Self-lubricated, non-corrosive, poly swivel bearing heavily plated steel to resist corrosion
Perfect for marines seats or barstool or your DIY chair projects
Mounting screws are not included

Specifications:

Its universal  4-1/2"   to    5 -1/4   " hole pattern design fits most seats.

6 -1/2 " x 6 - 1/2 " x 7/8" thick

Package included:

1 x Seat Swivel Base