Notch Zero Throw Weights are lead free with stainless steel weights. Notch's proprietary throw weight design with a Hi-Viz color pattern that doesn't exist in nature with graphic side design for better visibility. The weights are color coded according to weight and each one is made from extra-stitched 1000 Denier Nylon Cordura material with a welded ring for additional support. Notch Zero Throw Weights are tough enough to hold up to anything you can throw them at. Lifetime warranty.