The L Series from Titan Tool Supply is a Borescope with Viewing Angle 0 Degrees, 90 Degrees, Field of View(FOV) 42 to 50 Degree, Focal Length 0.118 to 0.236 Inches (3 to 6 mm), Probe / Insertion Tube Diameter 0.039 Inches, 0.078 Inches (1 mm, 2 mm), Probe / Insertion Tube Length 6 Inches (152 mm), 12 Inches (305 mm). More details for L Series can be seen below.