Digenite Thermo insulation contains ThunderonÂ® fiber for superior warmth and heat retention. Digenite Thermo insulation is a ceramic composite incorporating Copper Light (Sunlight and other Light) which Infrared Rays (Short and Long) which are invisible to the eye. By an exothermic heat generation from natural sunlight and body energies, generates heat and retains this heat. Digenite Thermo material absorbs these electric waves to generate heat. Furthermore, this ThunderonÂ® Digenite Thermo has strong anti-microbial and static electricity minimizing properties.