Long story short I noticed that there's a small circle rubber seal type of thing on the bottom of my holosun 515t , red reticle. Mine is partially ripped, I only took it off the stock mount cause the qd broke. I have a spare mount by adm so imma use that.

Does anyone know what that seal is for? I'm assuming purging or putting nitrogen or whatever gas they use into the optic. But idk.

I called holosun and tgey told me write an email. Did that 2 weeks ago. Wrote another email last Tuesday and friday. Still no reply so I called yesterday (monday) and the guy told me to write an email again. So I did. Kinda irritating they keep telling me to write an email and still no response.

 

Is that leading to the battery compartment?

I have a different holosun and the battery tray has a rubber ring.  The directions mention for sealing/protecting the battery.  I don't recall if watertight/proof, but generally protecting the battery compartment. 

Is that leading to the battery compartment?

I have a different holosun and the battery tray has a rubber ring.  The directions mention for sealing/protecting the battery.  I don't recall if watertight/proof, but generally protecting the battery compartment.

Dang sorry, I forgot to upload pic. But naw its on the bottom. My battery is like aimpoint t1/t2 style. But my controls for the actual dot is push buttons. I dont think they make this model anymore.

Its the one that actually looks like a circle. The other blob was me using it as a "paper plate". I was vibratiting my new light mount screws but my nozzle thingy on the vibratite broke and it this optic made a good tray as it was the closest thing to me lol

Did you ever figure anything out here? I have the exact question/ issue

Did you ever figure anything out here? I have the exact question/ issue

I emailed holosun. They never told me what is exactly below it. But I feel it was the purging port for it. No questions asked bout how it deterriorated .  they only asked for my serial number. Then gave me a link to do a RMA.

Gave me shipping label. Via USPS. Turn around time was about 2 weeks. No biggie. Also gave me a new battery and lens cloth.