20 oz stainless steel, durable and double-walled tumbler. Comes with lid, straw, and gift box. CARE TIPS: 1. Please do not microwave. 2. Hand wash the tumbler before first use. 3.The sliding piece could be taken off for washing. 1. After pouring in boiling water, let it cool down without the lid for at least 5 minutes. 2. Please leave some space at top of vessel for lid to avoid overflow. 3. Always keep the tumbler away from children when filled with hot liquids.