VBand Type-C Port Multifunctional CW Trainer Key Code Trainer Telegraph TrainerVBand Morse Type C Interface Multifunctional CW Trainer Vband Mobile Phone Computer Connector Code Trainer Telegraph Trainer Key Connection Descriptions: This trainer has two working modes. It can be used on computers and mobile phones for CW training. It is suitable for various systems and plug and play without drivers. If you need to use this trainer on a mobile phone, you need to prepare a dual Type c port data cable. If you use it on a computer,