MODEL "D"SALES A KIT FOR PRODUCT CODE: 2D4-3B57-14400000C; PRESSURE REDUCING REGULATOR,TFE GASKETS (OPT-45) 1/2" SIZE; BRONZE BODY & SPRING CHAMBER; B5 TRIM: BRASS WITH TFE SEAT,PHOS.BRONZE DIAPHRAGM; OPT-4: STABILIZER (RECOMMENDED FOR GASEOUS SERVICE ONLY);