Portable practice interface that connects to phones and computers for flexible Morse code training at home, in the classroom, or while traveling. Features a 3.5 mm interface to support standard telegraph keys; non3.5 mm setups can be connected with a simple adapter or conversion cable. Suitable for amateur radio enthusiasts and Morse code learners; supports automatic and manual recognition to accommodate different user preferences. USB Trainer enables seamless integration with the VBand software on the website, delivering stable performance for both paddles and straight keys. Key attributes: function and versatility for practice; compatibility with phones, computers, paddles, and straight keys; portable design for easy transport; reliable performance. Use scenarios: Individual practice at home using a laptop or smartphone. Classroom training with students using standard telegraph keys. Onthego practice while traveling, using a portable device and adapters as needed.