* MATERIAL: Foam with steel buckle * COMFORTABLE FOAM PADDING AND STURDY HOOKS:Comfortable padded sides for contoured fit around your ankles. Sturdy hooks fit over bars and buckles close the pads. * ALLEVIATE BACK PAINS AND MUSCLE SPASMS:If you have experienced these or other issues related to muscle or back pain, you can possibly relieve it and stretch neck, back and shoulder muscles with the fitness gravity boots. Hanging upside down has several benefits, such as stretching muscles, spreading compressed spinal discs apart, and relieving back pain. * SAFETY COMES FIRST: High strength stainless steel sturdy hooks and Safe Locking Clips for your safety. Enjoy your training life.