pulse lengths for lightsheer diode?

apparently there is a 30ms and a 100ms pulse length. why is one preferable over the other?


Actually, the newer Lightsheers should have Auto, 30ms, 100ms and 400ms. Auto is basically where the machine sets the pulse width to be half of the fluence. (i.e. if you have it set to 30 joules, the pulse with in auto is 15ms).
The longer pulse widths are supposed to be use on coarser hair, and people with darker skin.