Abstract: A handheld device which is capable of writing on a variety of surfaces using ink or graphite, as well as a tool for scribing, scratching, and scoring numerous materials such as metal, wood, or plastic. The handheld device may be used for piercing holes in softer materials such as leather or paper, for breaking harder materials such as ice or glass, for self-defense against a human or animal attacker, to pry open or wedge closely positioned objects, and to clean or scrape material off of another surface. The handheld device resembles a common wooden pencil, making its purpose discreet to an outside observer. The handheld device includes a cap that covers the writing implement side of the device, which both protects the writing implement and also contributes to the overall appearance as a common wooden pencil.

Abstract: A power supply and exchange system includes a supporting unit and a power supply unit. The supporting unit defines a connecting opening, and includes a rotatable holding seat defining multiple angularly spaced apart receiving slots. The power supply unit includes multiple energy modules detachably received in the receiving slots. A mounting seat of an unmanned aerial vehicle is mounted with one of the energy modules. The unmanned aerial vehicle can be positioned to allow the mounting seat to be aligned with the connecting opening for releasing the one of the energy modules, followed by rotating the holding seat for another one of the energy modules to be mounted to the mounting seat.