RIH Air Dryer System - 1/2" NPT Double Air Filters-5 Micron Particulate Filter& Air Pressure Regulator - Gauge(0-150 psi), Semi-Auto Drain, Poly Bowl,Bracket - 3 in 1 Two Unit (1/2" NPT): Amazon.com:
Filter Element 5 Micron for Pressure filter Regulator 1/4 BSP series | eBay
Amazon.com: NANPU 3/8" NPT Compressed Air Filter Regulator, 5 Micron Brass Element, 0-150 psi Gauge, Manual Drain, Metal Bracket : Tools & Home Improvement