I have seen the flip flops but I dont really have a need for one ever.I have multiple light setup and none of my grow areas are close to each other so I wouldnt have any use for it.I use digital switchable ballast so no real need for it. I know some people trying the new dutch method of alternating spaced lights where you have like 8-10 lights then you use flip flops to control the lights so only 5 are on at any one time they switch every other hour and the lights are setup in a pattern so you get overlap this way you cover twice as much are but use half the power. Just toy have a single flip flop isnt worth the money to me as I could get a whole second 600 watt setup for half the price of the flip flop