This product is a magnesium silicofluoride that reacts chemically with the free lime and calcium salts in hardened concrete to male a more dense and durable surface. It will effectively penetrate concrete and make it hard, free from dusting and highly resistant to corrosion and abrasion. The addition of a patented penetrating agent to magnesium silicofluoride makes it possible for its penetrating properties and hardening action to proceed to a greater depth than with conventional hardeners.