Manufacturer Prodigen. with Prodigen Weighted Vest. Burn your calories?. Increase your endurance and core strength?. Max out your work out performance?. Do it all with the Prodigen Weight Vest! STUFFED WITH IRON SANDS - Stuffed with chemical-free iron sands, this weighted vest is suitable for strength training, muscle building, stair climbing, weight loss, weightlifting, walking, running and more, helping improve cardio conditioning and body strength, giving you more power, speed, and agility.