Westbrass 1/2" Shower Arm Volume Control Trickle Valve, Polished Brass, D309-01 Shower arm volume control valve 1/2 in. IPS female from shower arm 1/2 in. IPS to shower head Adjusts flow from drizzle to full on Cannot be used as a positive shut off valve (by law) Shower   arm volume control valve 1/2   in. IPS female from shower arm 1/2   in. IPS to shower head Adjusts   flow from drizzle to full on Cannot   be used as a positive shut off valve (by law) Drizzle   protects from scalding Excellent   water saving device Solid   brass construction