All of our single shackles are made from 3/8" thick Laser Cut plate steel. We offer all our shackles in three different lengths to better suit your application. All bolt holes are ½" and can be easily drilled to a larger size if needed. We also offer a slight variation to our single shackles with the addition of a offset. This offset allows the user to reuse parts that they already have to minimize project cost, the offset allows you to use your factory spring hangers but interchange your leaf springs. Like all of our products, they are made in the USA from USA steel.