The inner liner of the cup is made of the most advanced SUS316 stainless steel material. Compared to 304 material, the 306 material of this product is more corrosion-resistant and heat-resistant, and is more commonly used in the health field. Design: Adopting double wall vacuum insulation technology, both inside and outside are thicker than traditional insulation cups. The surface of the cup body is sprayed with plastic material, and the plastic composition of the lid is BPA free food grade PP. Beautiful and healthy Function: Keep both hot and cold for up to 24 hours; The cup lid has a sealing effect to strictly prevent omissions; Comes with a buckle for easy carrying and hanging. Usage: Outdoor sports, indoor office and household use, business trips, camping, tourism, mountaineering, etc; As a gift to friends, parents, brothers, sisters, etc Satisfaction feedback: If you encounter any problems after purchasing, please feel free to contact us at any time. Your satisfaction is always our pursuit.