It made by stainless steel, We need wash more time, use Liquor and Spirits wash this flask.TOP GRADE MATERIALS: These flasks by are made out of premium quality stainless steel, ensuring that your experience will remain the greatest year after year. Non toxic, anticorrosion and anti-rust product.A grip-friendly matte black flask of 12oz, a funnel for easy use. ELEGANT & VERSATILE - The 12 oz flask brings and stores more your favorite beverage. Idea stainless steel flask for all outdoor activities, like Fishing, Camping, Boating, Hunting, Hiking, Tailgating and much more. UNISEX AND CLASSY DESIGN: Our engraved stainless steel matte flasks fit as good in a mans pocket as in the bag of an elegant woman . 100% LEAKPROOF - Every whiskey flask with thick stainless steel lid, air-pressured, laser welded and quality controlled. The cap seals tightly to make sure no vodka, whiskey, bourbon or other favorite beverage will leak out and get wasted.WORRY FREE 2 YEAR WARRANTY- 100% Guarantee If you are not completely satisfied, contact us immediately . Warm tips for first use and conservation instructions: 1. Rinse the inside with clean, soapy water before filling the flask for the first time. 2. Always empty the flask after use no severe dropping, no high heat, and no acid liquid for long term. and rinse thoroughly before refilling. 3. Do not keep alcohol in the flask longer than a period of 3 days and to clean and dry thoroughly when not used.