1.6 gaff meets U.S. federal standard for water conservation Quiet GO BLUE triple-filter diaphragm prevents water contaminants from clogging the diaphragm, extending its lifespan and lowering maintenance costs Standard 11-1/2 in. rough-in and 1-1/2” top spud Chrome-plated metal cover provides long-term durability Tamper-proof stop cap deters vandalism; Manual override button in case of power failure; Adjustable tailpiece allows for flexibility in installation; ADA compliant; 1.6 gpf closet flush volume; Clog-resistant triple filter diaphragm