The SCR,Selective Catelytic Reduction,is a catalytic converter that converts Nox exhaust fumes into harmless water and nitrogen by chemical reaction of urea in a catalyst in the exhaust gas steam to reduce pollution.Size:       16L,35L50L,80LMaterial:        LDPE Mechanical properties:       Good resistance to ultraviolet rays;       Perfect cold impact resistance;       Excellent thermal ageing properties Others       Resistance to vibration       Resistance to gravel       0.3 bar hydraulic test Standard: See symbol specified in ISO 2575 and see marking specified in ISO 22241-1. Blue is the recommended color for filler caps.