Features 1.Adopt breathable and soft fabric, comfortable and skin-friendly for all season long time wear, will not cause any irritation to your skin. 2.Built-in 111pcs magnets will release heat quickly with long lasting heating effect, effectively helping improve micro circulation and promote blood circulation to relax muscle fatigue and relieve the pain associated with joint and back problems. 3.Adjustable hook and loop type fastener straps, fast to release or close and free to adjust the tightness, 3 size variations can widely suit most users with custom fit. 4.Can be used to support shoulder, back and waist and maintain a better posture for improved sleep quality and body health, suitable for people who spend long time working before computer, sleep with incorrect position, suffer from neck and shoulder fatigue and cervical stiffness, etc. Specifications Material: Breathable Fabric, Magnets Color: Black Size: M/L/XL(Optional) M: 100*39cm/39.37x15.35inch, L: 110*39cm/43.31x15.35inch, XL:115*39cm/45.2715.35inch. Note: Please allow 1-3cm error due to manual measurement and make sure you do not mind before purchase. The color of the actual item may slightly vary from the images due to different computer screens and display settings. Thanks for your understanding! Package Included: 1* Magnetic Back Support 1* User Manual