I recently sent an Eotech EXPS3-0 to them for service. I only paid shipping one way.

I had mistakenly opened the nitrogen purge port, when removing the factory mount. I told them what I did and why, and asked them if they'd re-purge it for me. They sent me an RMA# and instructions.

I sent it with no hood, battery cap, or mount. I was honestly just too lazy to track down the original mount/hardware and reassemble it. I figured they'd fuss at me when they got it.

I didn't hear a peep, and the sight was promptly returned to me with a fresh purge, and fully re-assembled with a new mount, hood, and cap. Now I have extra parts and hardware.

Excellent service.

Good to hear of a favorable report like that. Aimpoint did something similar for me when a Safariland holster broke the front lens of a P-1 ACRO. I sent it to them in hopes it could just be repaired, but they sent me a new P-2.

I am curious, though, what the “nitrogen purge port” is, and why it’s something that a clueless user like me might open by mistake.

On Eotechs, there's a little screw on the bottom that grants access to the interior atmosphere of the sight. When I was switching to a different mount, I mistook it for a screw holding the factory mount to the optic. I just went to unscrewing everything without thinking.

Thanks. Always learning something new.