Quiet Pipes 1/2" M.I.P. shock absorber is the DIY solution that stops water surge pipe banging caused by quick-closing valves. Designed to use on drinking water lines, it has a triple O-ring sealed air chamber, maintaining a 60 PSI air charge and absorbs the high-pressure surge. Can be installed without opening any wall. Can be installed upside down or sideways without reducing the effectiveness. 1 per card. Installation instructions included. Manufactured to include no more than 0.25% weighted average lead content on wetted surfaces.