Complete pressure-assist flush system for 503 series tanks. It ONLY fits porcelain manufacturer Gerber 10” rough-in fixtures. (“Rough-in” refers to the measurement from the wall behind the toilet to the bolts that hold the toilet to the floor.) The system includes: Vessel-1.6 gpf Lower Supply NutTank Nut Flushmate-to-Tank Gasket Tank-to-Bowl Gasket NOTE: The Flushmate system is not designed to work as a replacement or upgrade for a conventional toilet. This unit is intended to be sold as a replacement system for an existing Flushmate. (Price subject to change without notice. Check stock before order)