Through modern technology you now have the ability to look inside most any hole that is .005" less than .25" Check the cylinder through the spark plug hole, valves and valve seats, see if oil is running down the valve stem, etc This is a live remote video with the following features: High resolution auto focus, color camera, 2-1/2" full color viewing monitor Equipped with a sealed, fluid proof, flexible, 24" long 6mm diameter shaft, high output LED illumination with dimming control, a mirror used to see 90° and a magnet for picking up steel parts weighing less then 1/4 lb