Royal, Regal and Sloan Prison Flushometers feature all the performance benefits of standard concealed, diaphragm model Flushometers with added durability to withstand rough environments;PERMEX synthetic rubber diaphragm with Dual Filtered Fixed Bypass;Valve body, Cover, Tailpiece and Control Stop shall be in compliance with ASTM Alloy Classification for Semi-Red Brass;Valve shall be in compliance to the applicable sections of ASSE 1037