Kenwood KWD-AE31 Audio Expansion ModuleThe Kenwood KWD AE31 is an optional secure cryptographic module designed for high level voice encryption in professional Kenwood two way radios, such as the NX 5000 series. It supports 256 bit AES (Advanced Encryption Standard) and 56 bit DES (Data Encryption Standard) to provide secure communications, often used in public safety applications.