Horton Crossbow Innovations Replacement String for Storm RDX (HCA-12215) Fits Storm RDX 40.875-inches long, GREEN COLOR Proper maintenance of your crossbow ensures that it continues to operate reliably, and replacing your worn out string is essential to upkeep Constructed from the OPTIMUM COMBINATION OF MATERIAL to give you the performance you demand Comes PRE-TWISTED FOR EASY INSTALLATION and out-of-the-package performance