Figure 1 shows the filter options available for HMD60. Figure 1. HMD60 filter options 1 Metal grid with PTFE membrane (Vaisala order code ASM212652SP). This is the default option delivered with HMD60. 2 Sintered stainless steel filter (Vaisala order code HM46670SP). 3 Sintered teflon filter (Vaisala order code DRW244938SP). Related referenceSpare parts and accessories