PREFERRED 3-1/2″ Post w/welded flange KIT gives your railing system a very durable foundation. The Post KIT will come with a two-piece BASE COVER and 2 composite leveling shims and instructions. POST CAP NOT Included, so you can add any style of Post Cap (see Post Caps). There are 4 color options with a textured finish will give you a beautiful finish to your project.  For Stair Rails, you will need a 43″ Post at the bottom, if using a 39″ Post on the top. This is needed to allow for the difference of the bottom step riser measurement. You might not need all 43 inches, but you will need more than 39 inches.