The GROHE GrohSafe 3.0 Shower Rough-in Valve is engineered for quick, easy installations no matter the situation. Compact body allows for a hassle-free fit even in tight spaces. Flat back ensures solid mounting on a standard cross brace, and installation on thin walls or steel is sturdy and secure. Made of DZR brass to resist corrosion, the GrohSafe 3.0 is equipped with a flush plug that allows you to test and flush lines with ease. Stainless steel fixation ring keeps flush plug and cartridge in place without screws. Cartridge sold separately.