Haith's Mineralised Tonic Grit supplies important minerals and trace elements essential to seed-eating birds guarding against mineral deficiency. It contains Calcium, Sodium, Iron, Magnesium, Potassium, Phosphorous, Iodine, Chlorine and Manganese. It does NOT contain seaside gravels which could have been contaminated with effluents or harmful pollutants. This product should be in every cage & aviary at all times. You cannot buy a better grit than Haith's Mineralised Tonic Grit!