Teslong NTG100H 26in Rigid USB Borescope Black/Metallic Silver TSNTG100H. 18 in to 3.94 in (30 mm to 100 mm) Depth of Field of the camera WITH 0.2 in (5 mm) side-view mirror: With lock ring on: 0 in to 0.28 in (0 mm to 7 mm) Without lock ring: 0 in to...