Product review (5 stars): Totally solved my tight space problem.
If you have very little clearance behind your dryer, this is great.  It's been in for 3 months now and I am very happy with the results.  I installed it with another elbow joint for the other end and a firm but flexible hose.  This allowed me to attach both ends with the hose and push the dryer back in place without any kinks in the hose.  I also used a generous amount of foil tape to really seal the seams.  I am glad I did as the laundry area is significantly less linty now.