Product review (3 stars): Only used the 90 inlet piece
I agree with what the other reviews have stated.  Buy foil duct tape and seal all the seams.  The part that connects to the dryer is not very deep which makes it difficult to insert in a secure way.  I didn't use it..  I ended up combining two products...Lowes had a better made telescoping vent, but it didn't have the 90 inlet I needed.  So I used the Lowes duct work (which had a better dryer connection) and just used the end piece from this item.  I wish they would just sell that piece.