GROHE SmartControl - Concealed Mixer for Shower or Bath (2 Valves, Square Shape, Set for Final Installation for GROHE Rapido SmartBox, Push for ON-OFF, Turn for Volume Adjustment), Chrome, 29148001 - Amazon.com
GROHE Grohtherm Smart Control Dual Function Thermostatic Trim with Control Module in Hard Graphite (Valve Not Included) 29137A00 - The Home Depot
Review: installing a Grohe shower - Professional Builder
GROHE - Rapido SmartBox - GROHE SmartControl - For your Shower | GROHE