luminous silicone bracelet work temperature: from -30 to 260 degree. hardness: 40~70 shore degree color: red, blue, green Luminous silicone BraceletThe product is R & D production by Shanghai liankun companymaterials:siliconework temperature: from -30 to 260 degree.hardness: 40~70 shore degreecolor: red, blue, green, yellow Luminous silicone Bracelet