The sequencer can be used to make a effect like the light is coming on a little at a time. When adding the sequencer to flex it can be setup to sequence 3 different length of sections if you like. (When power is applied to the sequencer it does its thing one time. Power is being reapplied to the flex strip in the picture simulation)
Works with:

TU211301
TU211300
RA400012
TU211303
RA4000-21