Borescopes are used for visual inspection work where the area to be inspected is inaccessible by other means, or where accessibility may require destructive, time consuming and/or expensive dismounting activities. Borescopes are mostly used in non-destructive testing techniques for recognizing defects or imperfections. Borescopes can be rigid, flexible and semi-rigid. A rigid borescope has an eyepiece on one end and an objective lens on the other linked together by a lens relay system. Flexible and semirigid scopes use fiber optics, instead of traditional lenses, to relay images and transmit light. Borescopes allow users to look inside areas of metal machined parts, castings and welded parts that are not visible with the naked eye. The importance to manufacturers and quality assurance personnel is fast, nondestructive visual inspection that ensures a part or component is free of burrs, cracks, surface finish irregularities and other imperfections.