SDML filters use 100% Molecular Sieves, which are recommended for refrigerating systems using HFC refrigerants, R134a, R404a, R410a etc.
SHM filters have been specially designed for refrigerating and A/C systems where high water adsorption is required. SHM filters do not contain aluminum oxide and can therefore be used with all types of compressors. They are therefore particularly suitable for systems using polyolester with additive; it is also a non-oil consuming additive compatible with R22.