Viva IML Tubes have a clear answer to address sustainability for any brands using tubes. All components are made of one material: polyproplyene (or PP resin symbolized by the cate- gory number 5). Of all plastic resins, PP is the lightest, takes the least amount of energy to produce, trans- port, generates the least amount of greenhouse gas. Viva IML Tubes can save 25 - 35% of energy compared to other forms of tubes.