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(R) 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(R) 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(R) bidet seat, there is a pre-attached copper supply built into the system. The separately sold TOTO WASHLET(R) Connection kit will complete your WASHLET(R) install (THU794). This DUOFIT(R) requires the toilet bowl, auto flush compatible washlet, and push plate to be purchased separately.