washdown model. Sanitary ceramics. this product works with industry standard in-wall carrier/tank systems such as those manufactured by Viega, Geberit and TOTO. Please refer to their respective compatibility charts.. Incl. fastening set for concealed mounting system. EN 997. Please order toilet seat separately.. This wall-mounted toilet is made of vitreous china. The wall-mounted toilet is 23 5/8" (600mm) x 14 5/8" (370mm). The product has a concealed trapway and a D-shape bowl. The product is with ceramic plus. The product has a water use of 1.6/0.8. gpf (6/3 lpf). The wall-mounted toilet is Villeroy & Boch model 6661U0.. meets and exceeds ASME A112.19.2/CSA B45.1 ASME A112.19.14, Certifications: IAPMO(cUPC), EPA Watersense, City of Los Angeles and others, Code Compliance: UPC, IPC, NSPC, NPC Canada and others, EPA - Watersense. washdown model. concealed trapway. D-shape bowl. one year limited warranty. min Water pressure: 8 psi. water surface: 4" x 5" (100 x 129mm). trap diameter: 2 1/8" (51mm). trap seal: 2 1/4" (57mm). minimum rough-in: 7" (180 mm) rough-in. rear outlet