This 17.6ft line-set cover kit had everything I needed for the short run (14ft) inside unit I installed. The two flexible "swivel joint" pieces were the most useful for the tight turns to go out the exterior wall and the final connection to the outside unit. It is also the only kit that had a wall penetration (straight ??) that allowed the line-set to come out of the wall and immediately run along the wall. I can't see a good use for the other wall penetration part. I wish extra elbows were available for purchase, but I found that the flexible duct could take the place of several elbows and ended up not needing anything extra.
The covers that are split (like this set) make the assembly extremely easy but I don't think they would be water-tight; thus limiting their exterior use. I only used the flexible duct, end cap and wall penetration for the exterior portion of the run. The longer 28 ft exterior run for my 2nd unit was placed in a 3"x4" vinyl downspout. Much harder to install, but 100% water-tight and less expensive.
Make sure you seal/fill the end cap opening to the outside unit or animals will enter the duct and eat the foam insulation (1/4 of my 10 yr old insulation was missing around the copper tubing).
The covers are very full when you place the line-set, the drain and 1/2" flexible water-tight conduit (for the control cable) inside. I cut and sealed a hole in the wall penetration part so that the conduit could be run directly to the electrical connection of the outside unit.
Lucas 
