The USEF 2-28-100 from USA Borescopes is a Borescope with Depth of Field(DOF) 5 to 100 mm, Viewing Angle 0 Degree, Field of View(FOV) 50 Degree, Operating Temperature -10 to 80 Degree C, Probe / Insertion Tube Diameter 2.8 mm. More details for USEF 2-28-100 can be seen below.