This is a two spring load lever. It holds a pair of either the 8412 or the 8413 springs. You may have one or two of these on your model. For guitars, use two - #8412 normal springs for .009's and .010 string sets. Use two #8413 heavy springs for bigger six string sets, light strung baritones and basses. There is also a three spring version if needed. You may need the load lever pin too.