The Hawkeye Pro Hardy Borescopes .250? (6.35 mm) from Gradient Lens Corporation is a Borescope with Viewing Angle 0 Degrees, Field of View(FOV) 50 Degree, Operating Temperature -20 to 120 Degree C, Probe / Insertion Tube Diameter .250 Inches (6.35 mm) (Scope), .313 (8.00 mm) (Mirror tube), Probe / Insertion Tube Length 7 Inches, 12 Inches, 17 Inches, 22 Inches. More details for Hawkeye Pro Hardy Borescopes .250? (6.35 mm) can be seen below.