What is a crash box used for in theatrical productions?

A crash box is specifically designed to create sound effects in theatrical productions. It is a prop or device that contains various materials, such as wood or metal, which, when dropped or struck, produce sounds that can enhance the performance. These sounds can mimic breaks or crashes, effectively contributing to the overall auditory experience for the audience.

The other options do not accurately describe the primary function of a crash box. While props, lighting, and costumes are all crucial elements of theatre, they are typically managed through different means that do not involve the crash box. The unique ability of a crash box to generate sound effects sets it apart as an essential tool for sound design in shows.