This recall is for Series 503 Flushmate III Pressure Assist flushing systems installed inside toilet tanks that were manufactured from July 2009 through April 2011. The units are rectangular, black, two-piece vessels made of injection molded plastic. Previously recalled systems were manufactured from October 1997 through June 2009. Recalled units have a date code/serial number that is 16 characters long and is located on the label on the top of the Flushmate III. The first six numerals of the serial number are the date code. The date code range for units included in this recall in MMDDYY format is 070109 (July 1, 2009) through 043011 (April 30, 2011). The date code range for previously recalled systems in MMDDYY format was 101497 (October 14, 1997) through 063009 (June 30, 2009). Units included in this recall were sold individually and installed in toilets manufactured by American Standard, Copperfit, Crane, Ecotech, Eljer, Gerber, Kohler, Lamosa, Mancesa, Mansfield, Orion, St. Thomas, Universal Rundle, Vitra, Vitromex, Vortens and Western Pottery.