Which accessory is NOT needed for the Titmus II-remote machine?

The calibration tool is not required for the Titmus II-remote machine because this type of vision testing equipment is designed to function accurately without frequent recalibration by the user. The Titmus II incorporates built-in calibration that ensures consistent performance over time. Users typically do not need a separate calibration tool for routine testing, as the device maintains its accuracy without such interventions.

In contrast, an extension cord might be needed for power supply purposes, ensuring the machine is reachable from an outlet. A screwdriver could be necessary for maintenance or minor repairs, while extra special OEM push/pull type bulbs are specific components used for optimal operation of the machine's lighting system.