Casall rubber bands are a simple but versatile resistance training tool which is great for stretching, muscle toning, and rehabilitation. These are an absolute favourite for professional trainers. o Reference resistance for medium: 7kg. Size & Weight o Product size: 30.0x5.0x0.1 cm o Product weight: 0.10 kg Care instruction Washable in cold water. Avoid direct sun light. Our resistance bands are made from a natural latex rubber, the material is sensitive to UV light and can change colour if directly exposed. We choose to use natural materials to avoid chemically produced materials but above all these amterials offer greater resistance. Note that If the bands loose colour it does not mean that they loose functionality at all.