Compact and portable: smaller than a standard eraser, this Morse oscillator fits easily in pencil cases, backpacks or bags, so you can practice anywhere. Type-C powered: compatible with mobile phone chargers, laptop chargers, power banks and computers, providing flexible power options for indoor and outdoor use. Audio-visual feedback: green LED lights in time with your key rhythm and provides both acoustic and visual feedback to improve Morse code timing and accuracy. Versatile keying: supports vertical straight keys, horizontal paddle keys and semi-automatic mechanical button operations, meeting different manual preferences. Use scenarios - On the go practice: train Morse code during commute or travel using a USB-C charger or power bank, with no wall outlet required. - Group or classroom training: pair with your chosen keying style (straight key, paddle, or button) for structured drills. - Field readiness and emergency prep: powered by a portable charger to practice or simulate signals in remote locations.