Final answer:
The hole inspection device that uses extension rods is a borescope, which is distinct from an endoscope that is used for medical examinations of the body's interior via natural orifices or incisions.
Step-by-step explanation:
The hole inspection device that uses extension rods attached to a head is called a borescope. A borescope is an optical device consisting of a rigid or flexible tube with an eyepiece on one end, an objective lens or camera at the other linked together by an optical or electrical system in between. The borescope is used to see in tight spaces and is commonly used in non-destructive testing techniques for recognizing defects or imperfections.
An endoscope, on the other hand, is an instrument used to examine the interior of a hollow organ or cavity of the body, and it makes use of optical fibers or a camera for visualization. Endoscopes are commonly used in medical procedures to explore the body through various orifices or minor incisions, and they can transmit light to interior parts, returning images for observation. This tool allows for minimally invasive examinations and can be used for diagnostic or therapeutic procedures, including surgeries.