The Eco Pro Tungsten Worm Weights are 97% pure eco friendly tungsten. Fray free, insert free and lead free, Eco Pro Tungsten weights offer serious advantages over lead. Eco Pro casts farther and more accurately than lead. Actually feel what you have been missing! Smaller, dense tungsten is super sensitive, allowing you to detect more strikes and catch more fish while greatly reducing hang ups! Special "seal coat" painting resists chips and scratches.