This unit strobes at the set frequency. It only strobes ½ of the time. If you set the strobe frequency to 3600 Flashes per Minute (FPM). It will flash just fine for ½ second and then NOT flash for ½ second. If you set the strobe frequency to 1800 Flashes per Minute (FPM). It will flash just fine for1 second and then NOT flash for 1 second. The flash is strong and steady. The operation/repair manual is included. I like to think that I could have fixed it if it didn’t work at all but the part time flashing is above my capabilities.