The AFW Planer is an innovative and precisely balanced piece of fishing gear. A lead weight acts as a keel and balance to keep the planer running straight at controlled depths. When the planer is in the water in diving position, water pressure against the blade forces the planer down. When a fish strikes, the balance is changed. The planer then trips and produces a slight upward drag, which allows you to fight your fish rather than a heavy lead sinker.