Often people ask us what is the appropriate scope for the application. Unless you are looking into gun barrels or homeowner consumer oriented applications- where life and death and safety are issues, you want to purchase a unit that is designed for critical applications. Sears and Home Depot are now selling chinese made CMOS videoscopes, that are great for looking inside many things, your car engine, your toilet, behind the wall for termites or mold, etc. They cost $300. Until recently, many industrial applications required rigid scopes of high quality lens systems for the best viewing results-such as german optical company Hanke Sass Wolf. Those scopes were written into inspection specifications for a particular aircraft or other component. However, the advent of less expensive "chip in the tip" scopes such as http://www.pacificborescopes.com/pb_IVS.pdf that have everything integrated into one unit have become available. The other consideration is the length inside the unit that you are inspecting you will need to view. Rigid scopes built before 1980 were built to 20 ft or more and weighed alot and were easy to break. The advent of Welch Alynn designing and marketing to industry (They developed it for colonoscopy first) one of the first true videoscopes for industrial inspection- approx 1984, using a color wheel spinning in front of a black and white CCD chip- became a huge seller. Later this company sold it's industrial product line to General Electric who have bought up many inspection equipment companies and trying to figure out how to sell them, along with not paying income taxes. Olympus is the other major player in the market- with a division in the U.S., however it really is a japanese company, both are the high end and have high end prices. Product quality is very good, but repair time and cost of ownership is high. Then there are lesser known companies, many of which are distributors of OEM products. In conclusion, if your application is critical- aerospace, aircraft, power generation, wind turbines or other such applications- choose a CCD chip scope even though it might cost abit more but a lower resolution CMOS sensor chip scope. Also make sure you order a scope of the correct length for the application as well. Shop around and see whats available, if you have not seen a unit, ask that Olympus and GE send someone out to demonstrate the unit to you, however if you buy you will pay between 15-50% premium more for that demo, but it is free to look, so just like looking for a new car, shop prices and don't let the salesman strong arm you to buy. The internet has many distributors who offer some very good competitive products, fast personal service, good technical support and can solve your problem over the telephone and save money in the process. All comments from people wishing to learn more about borescope inspections are welcome.