These are trim pieces which can be placed underneath the rail to created a "raised rail".  They are cut to any height up to 3" and come in 8 foot long strips.  Also included are cracked ice light diffuser acrylic which can be mounted behind the trim pieces.  10' long are also available.

A table that is 84"x42" requires 2 strips, any larger usually requires (3x) strips.  To determine how many you need, please determine the length required by measuring the perimeter of the inside of the rail.