Falcon Light fluorescent bulbs
 

I just finished a series of interviews using Interfit fluorescent lights with good result. The 28 Watt bulbs are produced by Falcon Eyes in Hong Kong. Anyone knows why these lamps do not flicker?

The most basic reason is from your camera's point of view the shutter and frame rate are set such that whatever the output driving frequency of the ballast of the fluorescent bulb, it is enough to not be a problem to your camera. The most likely explanation though is the electronic ballasts in the base of the bulbs are set to a high enough output frequency that its not an issue at any frame rate or shutter speed which is more and more the case with higher quality CFLs.