Only by passing these 5 tests can it be regarded as a real military telescope

Regular military telescopes need to pass 5 tests in order to meet military standards: high and low temperature, vibration, sealing test, and saline-alkali environment test.
The specific advantages are:

1. Good sealing performance: military telescopes, the lens barrel has high sealing performance, military products must reach the standard of 1.5M deep water immersion for 1 hour without water entering, because the sealing performance is good, it is isolated from the outside air, and the lens barrel can be used for a long time without deformed. Many military telescopes have been used for decades. Clear as new.