This faucet connector supply line is made from tough stainless steel wire, making it exceed all agency requirements for flexible water connectors. Every foot contains 220’ of stainless steel wire and every fitting is secured in place with a special radial crimp to ensure this connector lasts!^^Inner Core^The inner core's large diameter keeps water flowing. It also has a 3/8" female compression thread and a 1/2" iron pipe female straight thread for a more secure fit.