CHP-107 is a set of Standard Double Platform Rocker Springs. The springs are 8 gauge (9 turns) and are made of steel. The base measures 5 1/8" long by 3 9/16" wide. Sold in pairs, one for each side of the rocker platform. One pair is enough to complete one rocker. Mounting wood screws are included. Please note that you will need to check the inlcuded screws against your piece to ensure that they are the proper lenght and not too long.