Review on DGSL Garage Door Seals Bottom Rubber Weather Stripping Kit - Universal Weatherproof Threshold Buffering Sealing Rubber, 5/16 Inch T Ends, 3 3/4 Inch Width, 20 Ft, Black by Fred Novak

I was almost 16 feet actually 15 feet-10 inches. Remember that when you stretch the rubber, it stretches. install it. Mine expanded to 16 feet after installation. I would definitely do what others have suggested and order at least 6 inches more than necessary to make sure it will fit. Lubricate the track and DO NOT use WD40 as it's a solvent that will melt the rubber) and it's not too hard if you have two people. But I think the center round gasket/cushion in the gasket adds weight at the point where I would set it at 80% and the weight of the gasket is enough for it to sag and come out of the rail on one or both sides falls (see picture), especially when mounting at higher temperatures. After 3 or 4 attempts I finally got it fully installed. After opening/closing several times I'm afraid the seal will just fall out of the bead, but so far so good. And my track is intact - not bent at all. I think if I were to redo it I would get a gray or black seal without the center pad. If it gets out of hand I'll update this review. The quality of the product is good. As others have suggested the manufacturer should cut them at least 6 inches as they tend to stretch/shrink. I think the setting temperature can also affect the length a bit. My package said it was 20ft, although I ordered 16ft and got that exact length. Overall I am more or less satisfied with the product. EDIT UPDATE: See the second image I posted. When I opened my garage a week later today it fell off track and I probably opened and closed my garage a total of 10 times. I think I'll send it back.