Features: 1. Double-sided dot matrix heating can keep warm faster. 2. The length is about 46 cm, which can protect knees and legs and keep warm in all directions. 3. Knee protection: pads can protect knees, prevent arthritis and relieve joint pain. 4. Eliminate fatigue: The cushion is magnetic, which can improve blood circulation and help relax muscles and relieve fatigue. 5. Breathable design: The cushion is made of highly elastic fabric, which is soft and breathable. 6. Advanced materials: The cushion is made of tourmaline heat-sensitive material, which can contact with human skin, and the exercise of the body releases energy and makes the knees feel hot. 7.4 sizes: There are 4 sizes of knee pads to choose from, which are suitable for the whole family and meet different physical needs (suitable for weight 45-100kg). Specification: Material: breathable fiber cloth, warm fabric Length: about 46cm Features: self-heating, warm, soft and breathable. Size (approx.): M size (suitable for leg circumference: 39-42 cm (13.7-16.1 inches) L size (suitable for leg circumference: 43-48 cm (16.1-18.5 inches) XL size (suitable for leg circumference: 49-53 cm (18.5-21.6 inches) XXL size (suitable for leg circumference: 53-57 cm (20.9-22.4 inches) Function: protect knees, prevent arthritis and relieve joint pain Lists: 1 * Heated knee pads Notes: 1.The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2.Please allow slight manual measurement deviation for the data.