When selecting an airlock, you must prioritize material integrity and pressure differentials. For pharmaceutical or cleanroom applications, ensure the unit is constructed from 304 or 316L stainless steel to resist corrosion and facilitate sterilization. Key technical benchmarks include HEPA/ULPA filtration integration, interlocking door mechanisms (to prevent simultaneous opening), and pressure gauges (such as Magnehelic gauges) to monitor the 10-15 Pascal pressure gradient required to maintain ISO cleanliness standards.