120Hz US, 100Hz EU. It flickers at twice the main's frequency. It is because the LED drive/power supply electronics is too cheap to have enough capacitance to m

120Hz US, 100Hz EU. It flickers at twice the main's frequency. It is because the LED drive/power supply electronics is too cheap to have enough capacitance to maintain the LED powered while the alternating voltage is crossing zero. I used to get headache from flickering CFL lights in store when I was a kid. Those days only the worst LEDs make me uncomfortable. Some LED bulb will flicker with a really sharp cutoff, they are the worst. Many will flicker, but not down to zero light. This does make a difference.