The TESLONG NTG100H 26-inch long rigid rifle borescope is an ideal gunsmith tool that helps verify how well your rifle barrel has been cleaned. Carbon deposits build up as you shoot and can degrade your accuracy. This borescope helps you see the deposits in the lands and grooves of the rifling and is a great aid when cleaning your barrel. INNOVATIVE CLOSE-FOCUSING CAMERA SIDE-VIEW MIRROR With an adjustable, detachable, 90Adeg side-view mirror, you can check the barrel wall, or remove it to check the firing pin. 6-LED RING LIGHTS Adjustable for brightness and give the camera a perfect view of the darkest inspection areas. 26-INCH RIGID PROBE The 26-inch-long Mfg: Teslong