【Compact】Lightweight design, similar in size to a standard eraser but even thinner, making it exceptionally portable. Easily fits into pencil cases, bags, briefcases, key boxes, or even pockets, ideal compatible with on the go practice anywhere 【Morse Key Trainer】Features both audible buzzer feedback and a bright green LED light that flashes in sync with your rhythm. Double sound and visual cues help beginners master timing and technique while allowing experienced users to visualize their unique CW 【Application】Compatible with various manual Morse keys including vertical hand keys, horizontal paddle keys, and mechanical semi auto keys. No matter your preferred keying method, this trainer supports them all compatible with versatile practice 【Material】Made from PCB material. Each package includes a key connector, everything you need to start practicing right away 【Usage】compatible with use in diverses setting,whether indoors or outdoors,this device fit efcompatible withtlessly into any space where a Morse key is used,offering flexibility and convenience. Specification: Material: PCB Size Chart: 2.6cmx2.4cm/1.02inchx0.94inch Package Includes: 1 Manual CW Practice Tool 1 Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.