Application: Mix well. Do not use metal bowls/stirrers. Keep cap tightly closed when not in use. Store in a cool, dark place and keep away from excessive heat and light. Never return unused product to the bottle. Do not store mixed developer and hair color in a closed bottle as it may cause internal pressure and break the container. Warning: Contains Hydrogen Peroxide. Type: 6% (20 vol) 9% (30 vol) 12% (40 vol)