Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: Is this a one piece rod or two piece (in which one slips into the other to allow for extension)?
Document: You should be aware of correct orientation of the ends and chrome end covers. They must be put on correctly! Holes are tapered and offset. Install the single rear screw in each end first which will allow the unit to pivot into correct alignment and then carefully mark the other two holes. Undo the ends from the wall and put in the remaining anchors and then reaassemble with single holes first. This will allow the unit to pivot and take a lot of grief out of the unit moving around.
Look at the template, then hold the rod up and make sure you have it correct. One hole at one side, two at the other, and you'll be ok.  Templates make you want to drill one end backwards.
I really like the look of this shower curtain rod. It's nice that the screws are covered up by plates at each end. It was not hard to hang at all. It helps to have two people, one to insert the screws while the other holds the rod up. Other than that it was pretty simple.
This is a high quality item and it exceeded our expectations. One caveat:  As other reviewers have noted, do not try to put this rod system up by yourself unless you are a professional (and make sure there is no one nearby to hear you swear). This is a two-person job. Installing this rod isn't hard but you need four hands to get the right placement and to hold the two rods in position when the screws are tightened.
I replaced a single straight shower rod with the double one and really like it. It does make more room in the tub when showering and the double feature is nice by separating the liner from the outer curtain. It makes it easy to remove the liner for cleaning without having to take the curtain down also. The finish was nice and seems durable. Installation was simple but goes easier with two people.
This shower rod gives the illusion of much more room in the tub as well as allowing us to have the double curtain for the shower/  It is a high class piece of hardware and I am delighted with the finish on the rod. It was very easy to install.
I installed this product a couple weeks ago and it's been a nice improvement to the previous shower rod. Installation was slightly more complicated than it should have been due to discovering that my wall would not allow the use of the included molly bolts for 4 of the 6 securing points. Luckily, I had some suitable wood screws on hand and going directly into studs resulted in this thing being solid as a rock once installed.
Not many double curved shower rods out there! I like the double because you can leave the decorative curtain open when you shower and it lets in more light with just the liner closed. Fairly easy to put up and looks great! Price was very good compared to one or two other websites.
I install onto dry wall and was a bit more difficult then I expected. The set includes drywall insertions but I wished I placed additional support. tip: A two person job where while installing the bar itself have one person hold one end COMPLETELY flush to the wall while the other person screws in the other side. Knowing this would have saved me 30 minutes of frustration.
Make sure you have a mounting surface big enough to accommodate the very wide mounting bar. I have a piece of 1x4 trim around my tub and this was way too big to mount. Lowes carries a similar bar with a MUCH smaller mounting point.
Answer: It's a two piece pipe, as you say, where a slightly smaller end fits into the other.  The rods must be kept with the proper wall mount equipment for this reason.