Clean with warm soapy water followed by rinsing with clean water and drying with a soft cloth. All finishes are vulnerable to acid attack and some strong substances such as household cleaners or disinfectants can cause surfaces to go black or peel.
https://www.cphart.co.uk/dornbracht-concealed-part-for-xtool-thermostat-module-without-volume-control-34-inch/cDOR0103550397090Dornbracht Concealed Part for xTOOL Thermostat Module without Volume Control 3/4 Inch//www.cphart.co.uk//images/products/medium/cDOR0103550397090.jpg721.20721.20GBPInStock/shower-controls/cDOR0103550397090