The VJ-3 3.9mm from ViewTech Borescopes is a Borescope with Depth of Field(DOF) 7 to 80 mm, Field of View(FOV) 100 Degree x 75 Degree, Probe / Insertion Tube Temperature -10 to 50 Degree C, Operating Temperature -20 to 50 Degree C(Base Unit), Probe / Insertion Tube Diameter 3.9 mm. More details for VJ-3 3.9mm can be seen below.