Install the ARO 2000 Series 2 pc. Compressed Air Filter/Regulator and Lubricator Combination Unit with Gauge. Filters, regulators, lubricators, and piggybacks can be combined together easily. Such combinations are typically strung together in the F+R+L arrangement (three piece combination filter, regulator, and lubricator) and F/R+L (two piece combo) arrangement, although other configurations are also used depending on application needs. You can easily assemble this combination FRL using modular spacer kits, saving you time and money. This particular air compressor filter has a built-in gauge and auto drain to meet your needs.