Designed for mounting on the NW 25 port or inlet port of your helium leak detector. The low profile filter design provides a slight offset to the inlet port while maintaining the ports vertical orientation. The filter includes a 40 micron bronze filter tube which can be easily accessed from a side NW 40 port without removing the filter from the leak detector inlet connections. The bronze filter tube is ideal for helium leak testing since it is cleanable and reusable and will does not trap helium or outgas like other filter media.