Optimum Nutrition (ON) Serious Mass High Protein and High Calorie Mass Gainer - Budh Vihar DelhiPurity The neck of the tube is sealed with an induction vented liner inside the cap. The product has a plastic shrink wrap seal around the cap (outside) for protection. Who Needs Serious Mass: People with a very active metabolism that struggle to gain weight Athletes or anyone who has extremely high energy needs that can not be met only with food. How to Use: Prepare using an electric blender. Add fresh or frozen fruits, peanut butter, nuts & other