OVERVIEW EFM Aspen D3O Case Armour iPhone 13 Pro is integrated with patented D3O with 5G Signal Plus Technology, the only material to meet the industry 5G permittivity standard. It is proven to limit 5G signal loss by 37 per cent compared to any other case material in the market, giving your device optimum 5G signal, crystal clear audio and video, faster download speeds, prolonged battery life and best-in-class impact protection.