This mount is used for mounting the bars to pontoon boats with square rails as well as deck boats and bow riders. If you have a pontoon boat the mount clamps around the exposed square rial around the outside of your pontoon boat.
On boats like deck boats and bow riders, where there are no rod holders or square rails to attach to, the mount simply screws into the flat side gunnel area of your choice. The mounting plate will stay in place once screwed in, and the top part of the mount and bar top can be removed by sliding out a locking pin. This makes storage a breeze.