The Harbinger 5" Foam Core Belt features a flexible, ultra-light foam core to provide support to stabilize the core muscles and protect the back during heavy lifting. The belt is soft and comfortable, allowing full range of motion during functional strength training exercises. The belt helps support the back during during weightlifting and functional strength training. The breathable, plush tricot lining is soft against the skin and comfortable throughout even the most varied workouts. The adjustable, heavy-duty strap with heavy-gauge steel tensioning buckle fastens securely, customizing the fit for optimum support and stabilization. Harbinger weightlifting belts are designed to be worn tight around the waist. The more secure the belt, the more support and stabilization it provides.