So now I have to tell a Amazon customer service story.
I ordered a "Viridian C5L Universal Sub-Compact Green Laser Sight with Tactical Light" from Amazon (their price is outstanding). Because I am a cheap fuck, I ordered a like new, used one. This is the version with the auto-on/off "ECR" feature.
It came DOA. I returned it, but I ordered another used one.
It came. It was "inspected by _____" and it worked. I mounted it on my G19, turned it on and inserted the pistol into a Viridian-branded Galco King Tuk ECR capable holster - and it didn't turn off.
I then researched and found the SN where Viridian introduced that feature, several years ago, and found that this C5L was a early model before the ECR feature (and before Amazon carried them). Since it came in original Viridian packaging that said "ECR" on it (and had the ECR manual) and the packaging date was 2014 apparently someone had a early non-ECR model, wanted the newer ECR model, bought one and "returned" their early model in the new packaging.
I still got a good price, but I've had this happen before (Chinese airsoft replica T-1 returned as an actual T-1 in the Aimpoint box) and Amazon took care of it. So I let them know. They gave me a partial refund (a significant one).