I used these to replace the exact bulb I've used in my flashlight for years. But I can't turn it on for more than 5 minutes (10 max) without turning off the light. I can then turn it off and wait a few more hours and it will come back on, but it's a bit annoying that you can only use the light for 5-10 minutes at a time. and don't even think about turning it on all the way. or you may only have a full minute or 2. I will not buy them again.