ULTRA STRONG SHELL FABRIC AND CONSTRUCTION: Build with 1000D Nylon Cordura for long-lasting performance. The shell is tough and water-resistant and stitched with reinforced nylon threads and heavy-duty nylon straps. Large and durable YKK zippers. | WORK WITH YOUR TRAINING PROGRESS: Adjustable weight allows you to add or reduce sand to fit desired resistance and challenge. Great for beginner to advanced level | MULTIFUNCTIONAL TRAINING BAG: 7 multi-positioned reinforced handles allow you to perform various strength training. No experience? No worries, the workout guide is included to get you started, explore 10 most popular and effective workout poses in the guide | NO SAND LEAKAGE: Double velcro-sealed fill bag prevents leakage during the workout and keeps the sand in. Hit: fill the filler bag 70-80% at max for best performance, full-filling may cause bursting | 1 YEAR WARRANTY: Customer satisfaction is our No.1 Priority. We provide hassle-free refund service and excellent after-sale service. If you don't like it or want to replace it, contact us and we will make it right.