Which of these items is not a commodity?

The central clock system is identified as not being a commodity because it is a specialized electronic system designed for a specific purpose—providing synchronized time throughout a facility or building. Unlike commodities, which are interchangeable and typically mass-produced items like switches, conduit, and wire connectors, the central clock system often involves custom specifications, integration with other systems, and a degree of uniqueness based on the needs of the installation context. Commodities generally have a standardization that makes them easily replaceable and widely available in the marketplace, while specialized systems require tailored solutions and may have varying features and functionalities that differentiate them from more generic products.