Allow me to clear some misconceptions. When this item says 0-18, it's a bit of a poor description. It's 18" from center hole to center hole out of the box (overall length 24.5"). It's not expandable to 18" by pulling on the ends. If you want it less than 18", you MUST cut it. And, of course, it couldn't be less than about 5" in length just due to the connections. (A 0-5" periscope vent already exists, so 5-18 is a better description for this one). It says 2.5" profile (depth), supposedly allowing the dryer to sit back about an inch to 1.5 inches closer than the standard semi-rigid venting. I suppose that is dependent on your wall vent. If the wall vent does not allow the periscope vent to sit flat against the wall, any advantage is lost (see photo after Geek Squad installed the periscope vent). I had 3 Geek Squad installers for the new washer and dryer (separate trips for various reasons) and none of them recommended the periscope vent kit. They said they leak air, requiring a lot of foil tape, and don't really save you any room. In my case, that proved to be correct. I needed the space savings to close my closet doors, and in the end, the installers used foil flexible duct. The periscope vent may work in an ideal situation, but considering you may have to cut it and then tape it all over, it doesn't seem worth it...at least to me.