I was a bit worried after ordering and tried to email someone named Henry chain, no reply. I thought I hope I did not get ripped off. Not to worry was on the porch 6 days after ordering. I could hardly wait to put it on my 2015 F150. I read the instructions and thought this is too easy. My truck has a rail liner but does not hang too far over the inside lip of the bed metal. Once I opened the box and hauled out the tonneau cover I was surprised by how heavy duty it actually was. The rim seal is thick walled rubber tubing. I realized I only needed to apply the thinner weather seal tape along the top of the bed box along the cab window. My rail liner ends at the cab on the left and right sides of the bed. Once I cleaned that part of the bed I peeled a short piece of the seal paper off the seal tape and stuck it down. Took less than a minute to complete. I hoisted the cover into the bed and carefully set it down behind the cab. Following the instructions I was able to adjust the cover to fit perfectly on the bed rails. I hadn't realized that the cover latches were installed in key recessed areas along both sides of the cover, making the installation even easier than I thought. The latches pulled down and were very easy to adjust to the right tension. I set mine to where the rubber seal was not mashed completely yet still held firmly to the bed rails. The true test that I wanted to know the answer to was is this going to be water tight. I live in Portland, Oregon where it rains 2 feet a year and I installed the cover just before a heavy three day soaker hit. Not a drip in the bed, drove around in the rain on the highway 150 miles, checked the bed for water, again not a drop. One last thing, this is a sharp looking super strong and very well built cover that I expect will last for many years. I guess this review is the product of a very satisfied customer.