Z-Fit Material: This unibody weight vest by Zelus is filled with Z-fit Soft Iron material, which evenly distributes the weight to prevent shifting and reduce friction. Its ultra-thin, flat design ensures a snug and comfy fit, giving you more freedom to move compared to those iron sand vests Level Up Your Workouts: Boost your fitness routine with this 5 lb. weighted vest for women and men, adding resistance to help you burn more calories and build muscle. It's perfect for yoga, jogging, weightlifting, and more Ergonomic Design: Featuring a chest buckle strap and two side straps, our weight vest offers easy, customized adjustments to fit chest sizes from 32.3" to 39.4". Stay supported and move freely through any workout Comfort That Lasts: Enjoy lasting comfort with the soft yet wear-resistant spandex fabric, built to endure even the toughest workouts. Plus, it's hand-washable, odor-free, and designed to keep you fresh and focused Safe to Use: The high-visibility reflective stripes ensure you stay safe and easily seen while out and about. If you're just starting out, begin with lighter weights to progressively build your strength