Inspect bores for wear, damage and fouling Lyman's new Borescope provides active shooters with the means to carefully inspect the bores of their firearms for wear, throat erosion, tool marks, and other rifling or chamber damage, as well as for checking for fouling. The scope will fit 20 caliber and larger barrels and works with miniature camera technology. The display will show a clear image of the inside of the barrel and also allows you to take a photo of the bore. The image will be stored on a standard SD card and can later be viewed on a computer or laptop. Scope fits 20 caliber and larger barrels 20" long rod Miniature digital camera technology Images can be captured from the display and saved to a memory card