Harpic Duraguard 100% Limescale Remover - 750ml Harpic 100% Limescale Remover with its new DuraGuard formula, not only dissolves 100% of limescale in your toilet bowl and kills germs but also helps prevent and protect against the build-up of limescale stains for up to 150 flushes. Kills 99.9% of germs Attacks limescale better than bleach Removes stains