Geberit | Duofix In-Wall System with Sigma Concealed Tank, For 2x6 Construction. Design freedom – choose a toilet bowl from any leading ceramic manufacturer; pair with stylish Sigma series flush actuators or compatible flush buttons Easy cleaning – clean the entire floor with a damp mop, no bending or kneeling Improved accessibility – requires less space than a standard toilet, enhancing safety and comfort; adjustable bowl height meets personal preference or ADA guidelines Water savings – built-in dual-flush, 1.6 / 0.8 GPF or 1.28 / 0.8 GPF saves thousands of gallons every year Superior function – engineered Geberit fill and flush valves eliminate problematic chains and flappers that corrode and fail