These Tiamo milk jugs are powder coated on the outside and stainless steel on the inside. The colour array is designed to allow the busy barista to identify milk type at a glance (ie. Red = full cream, Blue = light, Grey = soy). No more colour taping or writing on jugs! They also have measuring scales etched into both the outside and inside of the jug to help pour the right amount, and therefore reduce waste.