Teslong 3-Mirror Kit For NTG100/150/450/500 Borescopes

Teslong 3-Mirror Kit for Rifle Borescopes This is a set of three 0.22 caliber mirrors to inspect the lands and grooves of a rifle barrel. These mirrors are compatible with NTG100, NTG150, NTG450, and NTG500 series rifle borescopes.  NOTE: These mirrors are NOT compatible with the NTG200H Focus and Fold borescope.DEPTH OF FIELD OF THE BORESCOPE WITH THE SIDE-VIEW MIRROR SET • Depth of Field of borescope's mirror with lock ring placed: 0in. to 0.28in. (0mm to 7.112mm)• Depth of Field of borescope's mirror without lock ring placed: 0in. to 0.39in. (0 mm to  9.906 mm)