The TOTO DuoFit In-Wall Tank Dual-Flush System with Copper Supply takes up less floor space, giving your bathroom a more open feel and making it easier to clean. This modern design uses TOTO’s Dual-Max flushing system, allowing you to proactively conserve water with a full or light flush option. Choose between a 0.9 GPF rinse or 1.28 GPF for tougher jobs. The DUOFIT harness allows you to select a mounting height of 15 in. to 19 in. This provides the opportunity for you to establish a comfortable bowl height for a wide array of individuals. The in-wall unit can support up to 880 lbs. when installed properly. The kit arrives ready to be installed within a 2 x 6 stud setting with a 2 in. x 6 in. polyethylene waste outlet. If you require installation within a 2 x 4 setting, you will need to additionally purchase TOTOs 2 x 4 PVC outlet kit (THU343). To enhance the installation with a WASHLET bidet seat, there is a pre-attached copper supply built into the system. The separately sold TOTO WASHLET Connection kit will complete your WASHLET install (THU805). This DUOFIT requires the toilet bowl and push plate to be purchased separately.