Over the last few years we have seen some amazing advancements with products using nanotechnology ingredients to protect many different surfaces. While we agree that they do an amazing job of repelling things like liquids, they aren't good for modern top coated leathers, as again they totally seal the surface, more so than any oil or silicones. So once again it cannot breathe and re-hydrate, leading to leather failure over time. Use them on your fabrics, or exterior surfaces, but not the leather.