Northwind Non-Slip Mug - Set of 6 The Northwind mug is perfect for coffee or tea. Made of break resistant melamine, this mug has a non-slip base. INSTRUCTIONS: This product is designed for table use, not adapt for cooking or direct fire. Microwave only 90 seconds. MAINTENANCE AND CLEANING: To extend the life of this article, it is recommended to avoid using abrasive cleaners. To prevent stains from coffee and tea we recommend washing immediately after use. This product is dishwasher-resistant.