What is a portfire used for in outdoor fireworks displays?

A portfire is specifically designed for igniting fireworks devices in outdoor displays. It is a type of fuse that is used to initiate the ignition of larger aerial shells or other firework devices in a controlled manner. The portfire is manufactured to ensure a reliable ignition source, allowing for a safer and more effective launch of fireworks.

Using a portfire enhances the safety of a fireworks display by providing a stable flame that can be lit from a safe distance, minimizing the risk for the operator. It is crucial in timing the show, as each portfire can be used to synchronize multiple devices, contributing to the overall effect and safety of the event.

The other options, while potentially related to fireworks, do not accurately describe the primary function of a portfire in the context of an outdoor fireworks display.