Silicone - Silicone is a synthetic compound best known for its ability to retain heat. Silicone is non porous which makes it hypoallergenic and easy to clean and sterilize by boiling or putting it in the dishwasher. Silicone has no detectable odor.
Steel - Stainless Steel is an alloy that is environmentally friendly and 100% recyclable. Stainless Steel is corrosion resistant and can be chilled or boiled.