I have the Photon X. Its rode on my vehicle keys now for a good long while. I took it off for a brief moment but its back. I had some early issued with it coming apart so I initially added rubber band to keep it closed. The rubber band disintegrated ( it was there a few years ) and I've not had that issue since. Not sure why the light came apart or why its now not an issue
. I don't put the keys in my pocket, they hang from a biner on my pants.
I love the light. Its been used more than I ever thought it would. I think I bought it in 2013 and other than the issue that seemed to resolve itself
its been flawless.
I've changed the batteries a few times and should mention I've actually had the light accidently activated so who knows for how long. I guess being on my keys it could have been pressed in any number of ways.
I know there are other lights that fall into this category but I do like my Photon X.
My light has strobe and can go from a high to very low mode.