The fence extender is made of plastic or a combination of wood and plastic and has several functions. First, extending the height of the fence for added privacy. The height can be extended above the original height of the fence as much as but not limited to 9". Second, the overall health of the pickets is extended due to protection against water going in between the pickets preventing warping and cracking. Next, is portection against wind damage because all the pickets are being held together by the fence extender and this prevents from nails that hold pickets in from sticking out. Last, but not least is the overall clean look and strait lines given to the entire fence, no more uneven pickets, and what color or design do you want? The sky is the limit with this product.