Royal Wulff Wristlok By keeping the wrist from falling back during the power application, the highest mechanical advantage is assured. Wristlok allows correct wrist movement only; between a bent-down position and a straight-up position. Proper wrist action on the backcast will lead to better control and accuracy on the forward cast. Acclaimed by instructors and students alike. Comfortable, durable, easy to use. One size fits all.Guaranteed to help improve your casting.