Relay Valve RG-2 (2) 3/8in-18 Supply Ports (2) 3/8in-18 Delivery Ports (1) 1/4in-18 Control Port 6 psig Cracking Pressure Part number: EM36370 OE MFG: MACK OEM Reference: 5396-KN28500 Cross Reference: MACK : 5396-KN28500; OTHER : FN18002A, KN28500 | PAI : 3637 Product Class: Air Valves & Kits The PAI EM36370 is an RG-2 relay valve with two 3/8 in-18 supply ports, two 3/8 in-18 delivery ports, one 1/4 in-18 control port, and a 6 psig cracking pressure. As heavy duty diesel truck parts, relay valves ordinarily use a control signal to manage compressed-air delivery within a vehicle air-brake system, while the listed port arrangement provides useful connection details for matching the valve to the intended plumbing. MACK lists 5396-KN28500 as the OEM reference; additional cross-references are FN18002A and KN28500.