Energy saving and environmentally friendly design: no batteries required, enabling practice message sending without battery maintenance. Compact and portable: lightweight build with a simple circuit, ideal for hand key practice and easy to carry. USB TypeC powered: can be powered by mobile phone chargers, laptop chargers, power banks, or computers. No constraints on charging method, suitable for indoors or outdoors and adaptable to various usage scenarios. Flexible key configurations: supports vertical hand key operation for vertical work and horizontal leftright operation of scanning keys and mechanical semiautomatic keys. Other forms of manual electric keys are accommodated within one device, without compromising compatibility. Easy to master regardless of the operation method. Practical use scenarios: training at home or in a workshop to improve hand key sending speed and accuracy. Outdoor or onthego practice using portable power sources such as power banks or laptops. Classroom or club sessions where different key configurations can be demonstrated and practiced with a single device.