Kohler K-4467-U-96 Wellworth 1.28 gpf Tank with Insuliner, Biscuit 12" rough-in Class Five(R) - provides tremendous bulk waste flushing performance and best-in-class bowl cleanliness 3-bolt Installation - Three pre-installed tank bolts save installation time Canister flush valve provides smooth flushing actuation with consistent water usage, flush after flush 1.28 gpf high-efficiency toilets provide significant water savings of up to 16,500 gallons per year versus an old 3.5-gallon toilet without sacrificing performance