Extension Ladders: Extension or “straight” ladders are normally the first type that comes to mind when you think of a ladder. This type is used to reach high places and most be leaned against some type of support; such as a house, wall, or tree before it can be used. Most extension ladders consist of two parts; the main piece is called the “base” and should always being firmly placed on the ground. The second part is called the “fly” and it is a moveable piece that can extend above the bed to allow the extension ladder to reach higher. Usually this sliding is done by use of a rope or hooks. This means most extension ladders have the ability to reach higher than you may first think when you see it “out of the box”.