Compact & Connectivity-Ready: Measures 110x62x28mm, featuring a standard 6.35mm jack for K4 manual keys and a 3.5mm audio port for wired headphones. USB Rechargeable & Smart Power: Includes a USB charging cable (compatible with phone adapters) with built-in lithium battery, auto-cutoff at full charge, and extended battery life for uninterrupted training. Adjustable & Portable: Customize volume/tone settings, enjoy a design, and practice Morse code anywhere with crisp, clear audio output. Color:White Material:Plastic+Metal Package Contents: 1 * Telegram Trainer 1 * USB Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.