Senchanting Women's 26 Double Steel Boned Underbust Corset for Waist training Hook and Eye closure Our size is not standard US Size. Our corsets, waist trainers, cinchers and shapers are sized by waist size, so please choose your corset according to your waistline. 26 Steel Bones: 20 Spiral Steel Bones, 4 Rigid Steel Bars Supporting Back, 2 Steel Bars 4 Layers of fabric. Fabric Material: Satin fabric.Strong Corset Cord Lacing Back: Ribbon Lacing.Fully adjustable. This waist trainer corsets can be used for waist training, during gym workout, for providing lumbar and back support, for posture correction, and as a tool for weight loss and waist slimming. You can read some of our top reviews for size reference. They might be very helpful! Thank you.