Shower Mixer Valve:
Pressure balance valve's cartridge monitor water pressure balance, helping to protect you from being scalded by
sudden changes in hot or cold water pressure
Hose:Stainless steel outer tubing, ensure durability and anti-corrosion,
*Handled Shower Holder
Low-Lead Solid Brass hard to rust and ensuring long-lasting durability

Method 1: 

In order to keep the surface of the shower clean, use a soft cloth, rub the surface with the flour, and rinse with water to keep the surface smooth;

Method 2: 

Brush the surface of the shower with a toothbrush and a toothpaste. Brush it for 3 minutes, rinse with water, and dry.