Mansfield Plumbing. The WaterSense-compliant Summit toilet offers 1.1- or 1.6-gpf options, reducing water usage up to 20% while flushing up to 800 grams of waste. The 3-inch tower is designed to seal tight with every flush, the company says, and won’t rust or corrode. The toilet comes in three configurations: ADA, elongated, and round front. 877.850.3060. www.mansfieldplumbing.com.