I changed the shock absorbers on my car and decided to mess with springs while I was there. These devices are made in the USA and are reasonably priced. They are almost 2 inches taller than my original springs which have about 160,000 miles on them. Not sure if it's because the originals are broken or what. I installed them anyway and now the car drives better with a load, which is good since I use it for work and carry a lot of gear in the trunk. I expect them to take root in a few months. In general, I am happy when camping.