Trevala S utilizes a proprietary construction type called C4S. C4S results in incredible hoop strength and incredibly sensitive rods. Because of this construction Shimano can use tiny rod diameters. These new smaller diameters lessen the overall weight which allows you to focus on fighting the fish and not your tackle. There is a Trevala S for fishing every size of butterfly jig. These very specific actions make success an even greater probability when spot fishing sunken stone outcroppings and wrecks. You will be amazed what these little rods are able to conquer.