Sturdy quality, durable 18/8 stainless steel interior and exterior, rust-proof and no metal taste, lifetime>5 years, better than using glass/plastic bottles Vacuum insulation technology for maximum temperature retention, hot 12 hours, cold 24 hours Wide mouth design makes it easy to clean and big ice cube filling The portable leakproof lid is toxin/bpa free, eco-friendly and safe to use We guarantee a full money-back if you\'re not 100% satisfied with SimpleDrink