This seat base will replace your original platform with this one that is 4 inches taller.  The seat base was formed and then CNC machined and anodized to make it durability and good looks.  It is a simple bolt on part that is easy to install using the original hardware. The part is engraved with the word Malibu.  See the malibu crew forum for reasons to have this bolt on part thread.   http://www.themalibucrew.com/forums/index.php?/topic/32483-bolster-seat-options/page__p__466379__hl__%2Bbolster+%2Bseat__fromsearch__1#entry466379

The seat and original base not included as pictured. The black anodized seat base is the part for sale on auction. In picture 2 shows the factory seat base and the bolt on replacement. For a custom seat base orders send a message through ebay.  this will fit most Malibu boats up to the year 2011.  Make sure your seat base is the same as the one pictured.  If you have a newer Malibu boat and would like a seat riser kit.