Made of high quality steel (chrome-molybdenum)All made with the friction ball retainer Tested to the highest specifications to deliver outstanding performance at the most competitive cost Lifetime Warranty Reducing adapters are not covered by the GP Warranty This set contains all 3/8" drive adapters plus extensions and universal joint. Each item use the friction ball retainer, which is a socket retention device. A spring loaded ball that line up with the socket retainer hole. Use caution when using this system because the socket is held in place only by spring pressure on the steel ball. Set contains the following: 3/8" F x 1/4" M adapter, 3/8" F x 1/2" M adapter, 3/8" x 3/8" universal joint, 1-3/4", 3" and 6" Extensions.