KOHLER Wellworth 1.28 GPF Single Flush Right-Hand Toilet Tank Only with Insuliner Tank Liner in WhiteKOHLER Wellworth 1. 28 GPF Toilet Tank with Insuliner The KOHLER Wellworth toilet tank offers classic design with modern efficiency. Featuring 1. 28 GPF and Insuliner tank lining, it conserves water without compromising performance. Its right hand flush lever and gravity fed technology ensure a powerful flush every time. Key Features: Water Efficiency: 1. 28 gallons per flush saves up to 16,500 gallons per year. Durable Construction: Made from