1. It is safe. Material is what makes products different. LOCK&LOCK uses heat resistant glass that does not have a risk of breaking itself or spreading fragments even if it means bearing a greater cost. 2. It is light. Heat resistant glass is more than 10% lighter than tempered glass Lifting a great weight off of users wrists. 3. It is clear. LOCK&LOCK oven glass is less likely to be become murky. It always stays as clear and pure as new one. 4. It heats up less. With its low permittivity It makes food warmer while the container itself gets less heated when used in the microwave. 5. It is heat resistant. As LOCK&LOCK oven glass is made of borosilicate glass that has a strong heat resistance It can strongly withstand the heat and rapid temperature change. Therefore You can use it not only in the microwave but also in the oven.