Fitment: Suitable for most 7x7 boat seat base plate and is fitted with an extension support rod for lock in 3/4inch boat seat post base holes. The marine seat swivel mount is highly practical and provides a great view when planning trips for fishing and leisure. Marine grade boat seat pin mount: seat base pedestal is made from 3.1mm thickness steel with black e-coated for rustproof and to withstand harsh marine conditions. Great boat accessory for pontoon/fishing/jon/ boat deck dock: The lock-in 3/4inch pin boat seat mount replaces existing boat seat & add seat on boarding, allowing you to have boat seat accessories to enjoy fishing boating cruising time. swivel boat seat mount plated: The shock-absorbing spring structure withstand both ride and structure pressure, gives extra cushioning and ensures stability. And seat swivel base mount with high strength steel pin to hold seat securely. Easy to install: The marine seat mount plated perfectly to the seat base and fits into the seat post, align the seat holes with the seats and rod holes, and install seat pedestal base in the direction of the arrows.