Which of the following is not an inspection item before daily operation of a stacker?

The headlifting (overhead guard) is not a standard inspection item that operators typically check before the daily operation of a stacker. This component is primarily a safety feature designed to protect the operator and the load during operation, ensuring that if an object were to fall, it would not strike the operator. While it is crucial for overall safety, it is generally not something that changes frequently and is not subject to daily checks like other components.

In contrast, the condition of the brakes, oil levels, and lights functionality are essential for the safe and effective operation of a stacker. Checking the brakes ensures that the operator can safely stop the stacker as needed. Monitoring the oil level is vital for proper mechanical function, as insufficient oil can lead to equipment failure or malfunction. Ensuring that the lights are functioning allows for safe visibility and communication during operation, especially in environments with limited lighting. Thus, while all components of a stacker are important, the headlifting guard is typically assessed less frequently than the others.