It is a 100% stainless steel fridge bottle. Purely leak proof. This bottle is 100% rust proof with food grade guarantee. Easy to clean, Durable, Air tight, Easy to Carry, Cools Faster, Best used in Office, House hold & Gifting purpose. Reduce use of one-time plastic by carrying your own fresh water in this cool bottle. The bottle is dishwasher safe and can be stored in the freezer as well.