Super premium flask with a mix of steel and bamboo304 grade steel used inside with natural bamboo outsideFully Vacuumized, retains temperature for 12-24 hours! (12 hours hot and 24 hours cold)Natural bamboo on the body and lid gives a very elegant lookTea strainer allows for both hot and cold detox tea brewsRust free, BPA free, leakproof constructionCapacity: 500 ml (approx)