Minimalistic design, but impractical, not a clever idea, low brightness, barely acceptable. It turns on and switches between modes (4 modes) by operating the plunger which opposes a strong resistance to your movement. No external switches, each time you have to turn it on, and want white light, you have to stretch it (extracting half of the body inserted in the other half) and, to turn off the light, you have to do the opposite, compress this kind of plunger, hard braked with a rubber element. Next time it will not turn back on with the last used mode, white light, if you do not wait 3 min. but in the second mode, orange light. On the next step you'll have a slow variation of colors, randomly and the fourth the constant flashing of the red light. So each time, to turn it back on with white light (or one of the other three modes) you have to repeat the entire cicle of 4 steps, operating the plunger it 4 times, or wait 3 minutes for an auto reset. Just absurd and annoying!