Our bow strings are made from the proven BCY 452x we have found it to be the only string material to not stretch. It also give you the max speed out of your bow. All strings are pre stretched to 500 pounds this provides you with a string that settles in 50 shots or less. We use # 3D serving for its strength and small diameter giving you the max speed and performance out of your bow. The center serving is made with halo serving for strength and it provides the most clean arrow release for improved arrow flight. All end loops are served for easy tuning. We provide the most high quality string for a great price. Each set of strings are built to order allow 5 business days to ship.