I purchased a straight piece and 2 end caps and I watched a video demo on one of the websites of an internet company who sold these items. It arrived in a very timely manner. I inserted each end of the door shelf into the groove on each end cap--like they did in the video. It "clicked into" place easily. Then I inserted each end cap into the little opening on each side of the refrigerator door--again, just like the video. It inserted very easily and clicked into place very securely. And voila!!!!! I now have a lot more room in my old refrigerator to store various bottles of things. Very easy and simple.