My led on both my pipes blinks after 5 seconds, and i dont get that great of a hit, i feel ripped off, i bought 2 of em u would think i would get at least 1 good one.I'm still trying to decide on that one - a lot of people claim theirs do, but the LED doesn't cut off on mine anyway, and I don't seem to be able to take a long enough draw to notice the atomizer cutting out after x seconds (but that's possibly because my mouth is already full of vapour.) Possibly there are variations on the basic model .)