Defi Yield Aggregators Explained: How They Work and Risks To Consider Hydro Flask Micro Hydro 200 Ml Hyf404. Hydro Flask Micro Hydro (200ml) an ultra small thermos from Hydro Flask Japan that can handle hot and cold drinks in a pocket sized format. Minimalist design and maximum functionality in a design that you can clip onto your backpack or bag and always have a drink on hand. Stainless steel construction Double wall TempShield vacuum insulation Impermeable cap Keeps your drink cold for up to 7 hours and warm for up to 7 hours Durable design Dishwasher safe Safe and recyclable materials Not suitable for use on the stove, in the microwave or freezer Recommended for children from 3 years of age Hydro Flask Lifetime Warranty Volume: 200 ml Weight: approx. 200 g