describe Specifications: S, M, L, XL characteristic 1. Effectively prevent excessive extension of the knee joint and protect it from damage. 2. Scientific design, in line with ergonomic principles, comfortable and breathable, comfortable to wear. 3. Adjustable fixed force, adjusted according to individual needs, providing personalized care. 4. Correct knee joint posture, help restore knee joint function, and reduce pain. 5. Suitable for various sports and daily occasions, suitable for athletes, professionals, and the elderly to use. Comment: 1. The manual measurement tolerance is 2-5g. Please don't mind your replacement. Due to differences between different displays, the image may not reflect the actual color of the item. Thank you. 3. SKU color refers to the color of the product packaging The package includes: 1 * Knee over extension orthotic device