Stainless steel is an excellent choice of material for an eco-friendly water bottle. The material is lightweight enough that it can be carried to and from the yoga studio easily, and it will help your drink to stay hot or cold for an extended period of time. Stainless steel water bottles also come in variety of exciting patterns and colourways to suit your style. Glass water bottles are also a good option to think about when looking for an environmentally friendly reusable water bottle, though they are a little heavier to carry around.