The HammerSTOP™ supply line hose eliminates water hammer (banging pipes) with an in-line patented piston action that absorbs unexpected surges in water pressure. The HammerSTOP™ features a water hammer arrester built into the 5 ft. hot and cold water supply lines for a Washing Machine. Unlike any other water connector hose, HammerSTOP™ features a proprietary UltraCore™ liner, resistant to chemicals and leaves no odor in the water; it’s also lead and BPA free!