Which of the following is NOT a type of sight on a gun?

A scope mount is not a type of sight; rather, it is a component used to attach a sighting device, such as a telescopic sight, to a firearm. The scope mount plays a vital role in securing various types of sights to ensure they are stable and properly aligned for accurate shooting.

In contrast, open sights, peep sights, and telescopic sights are all distinct types of sighting systems used directly for aiming. Open sights typically consist of a front and rear sight aligned along the barrel, while peep sights use a small aperture through which the shooter looks to align the target and front sight. Telescopic sights use lenses to magnify the target, providing greater accuracy, especially at long distances. Understanding these categories helps clarify the function and purpose of each sighting mechanism on firearms.