Chris CzeczugaSeptember 19, 2018 at 7:50 am 5 out of 5 I installed these on my 2010 Toyota Tundra SR5 as an alternative to an airbag system for hauling a 33′ toy hauler with a 1500# tongue weight. I am a Plastics Engineer so when I did my research on the materials utilized for this project I was pleased to find that they used an engineering grade PU (polyurethane) which has progressive dampening (resists load more and more as it is compressed). I’ve been using them for three years now and they’ve held up without issue. I’d strongly recommend them to anyone who wishes to haul something that will put a load on their bumper that is near it’s limit or simply want a smoother ride when there is a load in the back of the truck. They also provide a comfortable ride when not loaded.