I know it happens once in a while. I have seen a couple of other videos online where folks show their Armasight Zeus thermal scopes and no objective lens cap. Thermal scopes tend to have proprietary lens caps, nothing you can replace generically and the replacement can be expensive from the manufacturer. One of the rubber arms that holds the lens cap on my Armasight Zeus 75mm scope broke a few months ago after 2 years of use. Well that was a pain. It would just dangle off to the side and I was afraid of the other arm getting broken and loosing the entire cap, so I removed everything and would leave the cap in my rifle bag when I would go hunt. That meant leaving the very expensive Germanium lens exposed during periods of my hunt when I did not want it exposed. A flip cap would be cool, but Butler Creek didn't make anything that would fit over the lip of the bell on the 75mm. Bummer. Besides, the Butler Creek caps are somewhat fragile themselves and don't take well to twisting or lateral pressure. I have BC's on other rifles and have had to replace a couple because I managed to break them off. BCs are better than most other lens caps, but I am not delicate with my gear, so I really wanted something that would hold up to crawling through the briars without being torn off.

I spent a while looking for solutions and finally found one that looked interesting when I found this video ...



I checked the sizes. Nothing actually looks like it will fit the bell and lip of the Zeus 75mm but I ordered the largest size (Vortex Defender Flip Cap Objective Lens 56, 62-66 mm)...

https://smile.amazon.com/Vortex-Def...-4&keywords=vortex+defender+flip+cap

The skirt of the Defender lens cap that fits over the bell is a flexible rubber. It took a little work, but I got it on and it appears that it is going to work just fine! Here are pics showing the cap closed, open, and locked back.



I have hunted with it several times so far and find that it works perfectly. It even did well in the rain. So I am quite pleased with the result.

I really like the durability aspect of the Vortex Defender, plus having a flip cap for my thermal. Of course they make different sizes and so you can replace the original dedicated scope caps on various sizes of thermal scopes from several different manufacturers. At which time I break the Butler Creek cap on my IR Hunter, if that happens, a Vortex will be replacing it. I will be adding one to my Armasight Zeus 2 as well simply because I prefer the flip cap to what came on the scope.

Good info. I use Butler Creek flip caps on all my scopes and they work well, but now and then I break one. I'll start replacing them with the Vortex caps.

I have very little clearance on one of my NXS scope and barrel, I would say about 2 mm clearance. What scope cover will work? I guess some mods will be needed to make it fit in between.