The TOTO DuoFit In-Wall Tank with Auto Flush Ready 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. Auto Flush option provides a hands-free automatic flush after every use. No need to touch buttons or handles, and never worry about someone forgetting to flush.The DUOFIT® harness allows you to select a mounting height of 15 to 19 inches. 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 880lbs when installed properly. The kit arrives ready to be installed within a 2” x 6” stud setting with a 2" x 6" polyethylene waste outlet. If you require installation within a 2” x 4” setting, you will need to additionally purchase TOTO’s 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 (THU794). This DUOFIT® requires the toilet bowl, auto flush compatible washlet, and push plate to be purchased separately.