Our springs are made from Zinc Plated Steel. They are 7" Long x 1.5" Diameter weighing a total of 7 lbs. The zinc plating provides your spring with an extra layer of protection that usually makes them last longer. These springs are very durable and custom-manufactured, which allows these springs to bring comfort to your swing. They are made in the USA and will hold up to 600 lbs. They will ship in the same box as your swing.