Milton 3/8" NPT Deluxe Polycarbonate FRL Trio. 3/8" NPT Deluxe FRL trio is a filter, regulator and lubricator all in one. The filter has an automatic overnight drain, the regulator is the relieving type and the lubricator is drip style. This pre-assembled unit has polycarbonate bowls with metal bowl guards and includes a gauge. Offers a maximum of 150 PSI and 75 SCFM. 40 micron filter element..