A straight rail system is designed only to go straight up a staircase.  If your staircase has a turn, curve or landing then you will need to move to the curved rail system.  The straight rail stair lift is the most common type and the most cost effective and has the fastest installation.  Some situations two straight rail stairlifts can replace the need for a curved rail stairlift.

A curved rail system allows you to go around curves and turns on a staircase without having to get off of the chair.  This style of stair lift is also required when you have a landing as you go up the stairs.  Some people use this type of unit to park the chair at the top or bottom of the staircase so the chair is out of the way when not in use.

Outdoor stair lifts are used when you need to get up  a staircase that is outdoors, so whether you need it to get up the front porch steps or down an outdoor staircase to the basement, these units are designed to be used in the elements.  There construction allows the unit to get wet and still work. A cover is provided to help protect it.