I purchased these on October 30th, as a five-piece set, well in advance of my winter above ground pool closing, so I'd have them available when I was ready to close my pool. Unfortunately, that meant that I didn't unpack them and fill them with water until this past weekend. Quality/Useability: Two of the five (20 feet of pool cover tubing) were duds out of the package. The first 10' tube had a split (>3" long) in one half of the two-tube system, right at the center vinyl-weld seal, the other 10' tube has a seeping leak around the outside, best I can determine, at the filler neck. I was very careful to open all of these on a heavy tarp to ensure they were protected while I test-filled them with low-pressure running water, before un-filling them and placing them on the pool ledge - so it was immediately apparent that these two issues were due to a manufacturing defect. Since these are designed to "counter-balance" each other, over the pool cover and on top of the pool ledge, having only one of two tubes filled with water makes this pretty much a non-starter when only one tube-side is functioning. Not sure the seller will help here, but having 2/5 of a product non-functional, out of the package, isn't the way to sell product. Caution: Above-ground pool install, with some or no decking, is not for the weak. My pool is 18'x35' (~100 circumferential feet) x 55” to the top of the ledge. Only 1/3 is decked and the remainder is open-sided. Water, in quantity, gets heavy, and these tubes are very flexible when filled, so forewarned is fore-armed. Having done this by myself, I strongly recommend doing this with two people for ease of install. Otherwise, plan on a full-body workout before you finally get these settled into place on the pool ledge. :) Install: Lay these out flat on the pool ledge, put two tube sets, with the filler necks adjacent to each other so you'll be able to fill both tube sets (four tubes) from the same location. You want to gently fill these, not flood them quickly - a 1/2" stream of water seems to work best. Make sure you have some way to turn-off the hose at the hose-end - it just makes it a lot less "wet" - then fill them to 1/2 capacity (recommended to ensure that they don't burst during freezing periods). If you're doing this by yourself, be prepared to stop filling, and catch/shift the tube so it remains on-ledge. As water ebbs and flows back and forth in the tube, it will cause the double tube to shift, and in many cases, to drop-off into the pool and cover. It can also go the other way and fall off completely so be prepared for either eventuality. Having an extra helper would definitely help to keep the tube on-ledge, and to help shape the tube to the ledge contour as you’re filling them. Alternatively, with two people, you could conceivably fill the tube with water, then, together, hoist it into place and adjust it on the ledge. Final Thoughts: While these are made in China, I had hoped for better quality control on the end-product. It was frustrating that two of the five tubes were bad – it took 1/5 of the coverage out of my winter cover protection system until I get these replaced. In the interim, I’m using bricks wrapped in towels. If these last through this season, I’m going to re-think using these, as the utility just doesn’t seem to be there. Note: I also purchased a 5-pack of 8' double tubes from another seller, those were perfect.
