Product review (5 stars): Just what you need, but also purchase vent clamps.
We got tired of our old, inflexible ducting, which would fall out of the dryer anytime it moved.  This Dundas Jafine ducting has been wonderful because it's flexible and is of a high quality.  Note, however, that the ducting only comes with temporary clamps, so you'll want to separately purchase dryer vent clamps.