EFM Seoul Crystalex Clear Case Armour with all new Crystalex D3O û The worlds most protective transparent material. Market leading UV resistance, non-tinting and with a 200% greater dye transfer resistance than conventional TPU materials. The Seoul ccase provides clarity that lasts. EFM Seoul Crystalex Clear Case Armour has an internal geometry pattern that creates miniature air pockets to provide an additional layer of impact protection. It also reflects the light providing an eye-catching sparkle.