Hey, what do you think of cheap stuff like this O2 detector? Is it junk, or is it actually any good?

Hey folks. I work at a cave and were changing our flashlights out - current standards request we use red light around bats and keep the light at a minimum. In our cave we dont need particularly strong lights, its better if theyre not so we cant disturb wildlife. I need a flashlight and not a headlamp.

Having a light that can switch from red to white would be great, and one that also can change the beam focus as well. If there are only red flashlights that do this, and not ones that switch between red/white, id still like to know. I already posted to r/flashlights but theyve mostly recommended headlamps. sigh. Any recommendations or even lifehacks to make a light red that you have would be super helpful!