Progressive High-heat silicone bulbs are microwave safe for heating toppings; fill the frosting bulbs with icing or warm ganache before piping. Frosting bulb can be used in the microwave; holds approximately 3/4 cup. Store tips inside the bulb when not in use; dishwasher safe.Important Prop 65 information for California residents: This product can expose you to chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov