Objective Lens O-Ring

Overview

This is the seal that closes the objective lens assembly into the housing. Its whole job is to keep moisture and dust from getting past the objective and into the optical path. Seals are a wear item: they harden with time and with heat cycling and lose their resilience, and a seal that has gone hard no longer follows the surfaces it is supposed to follow. Moisture that gets past it ends up in the optical path, behind an element you cannot reach without opening the front of the goggle. That is why this is a replace-on-sight item: any time the objective has been out, fit a new one rather than putting the old one back.

Key Features

1) Seals the objective lens assembly to the housing and keeps moisture and dust out of the optical path;

2) A genuine wear item rather than a permanent part, because seals harden and lose resilience with age and heat cycling;

3) Replace it as a matter of course whenever the objective has been removed, even if the old one still looks fine;

4) A hardened seal no longer follows its seat, which is how moisture gets past the objective after a service is finished;

5) Fits ARGUS BNVD-1431 MK2 and PVS-14 pattern monocular housings;

What's in the Box

One objective lens seal

How to Operate

1) Fit a new seal any time the objective assembly has been removed rather than putting the old one back;

2) Wipe the groove and the mating face clean so nothing is trapped underneath the seal;

3) Seat it evenly the whole way round before refitting the objective, and watch that it is not pinched or twisted as the objective draws down;

Compatibility

Fits ARGUS BNVD-1431 MK2 and PVS-14 pattern monocular housings.

Why the ARGUS Part

Stock these several at a time rather than one per job, since the bench rule is a new seal every time the objective comes off.

Shipping note: this item currently cannot be shipped to Japan or Taiwan.