Much cheaper at Bass Pro, buy two and shipping free...
Bass Pro Shops Jon Boat Seat Clamp | Bass Pro Shops likely less other places. Marine Raider Adjustable Boat Seat Mount | Academy or ???
I have two that we use in the paddle jon, issue we had was hit something or rough water the clamp would pop loose, PIA. However we now have a rachet strap that we cut down to fit, ran under seat no more issues. It works fine, especially to decide where we want seats, but the pin type are better once you are sure where you want them