This term describes a leaf spring style where one end of the spring has the “traditional” eye and the other end comprises the open leaf or leaves of the spring forming a “tail” which slides in a “keeper” or “hanger” which is welded to the chassis of the trailer. This style of spring is very simple and long wearing, and is available in both black paint and Dacromet Coated finish. Slipper springs can be joined on a multi axle trailer with the tail of the front spring sliding over the eye of the rear spring. Alternatively these springs can be attached to the trailer as individual sets. This style of spring arrangement is a simple and low cost solution to multi-axle trailer suspension.