The Block Plane is one of the most useful planers you are going to buy. A planer is used to reduce the thickness of an edge of something. It shaves wood a little at a time smoothly and cleanly if the blade is kept sharp and you don't try and shave too much off at a time. The planer, or block plane, is about 6” long with a flat bottom and a small slit where the blade edge produces out to make contact with the wood. It is adjustable and has a handy knob on the front to hold onto.