Regency ® P42-4 Zero Clearance Direct Vent Gas Fireplace 116-7/8"(173mm) dia.Flue pipe4" (102mm)dia. flue pipe Termination CapPart #946-523/PAstroCapspringspacerWall Thimble (2 pc)INSTALLATIONVENTINGRegency ® Direct Vent System (Flex) Horizontal Terminations OnlyThese venting systems, in combination with the P42 Direct Vent GasFireplace, have been tested and listed as a direct vent heater systemby Warnock Hersey. The location of the termination cap must conform tothe requirements in the Vent Terminal Locations diagram in the "ExteriorVent Termination Locations" section.Regency ® Direct Vent (Flex) System Termination Kit (Part # 946-515)includes all the parts needed to install the P42 with a maximumrun of 4 feet.1) 6-7/8" dia. flexible liner (4 ft. length)2) 4" dia. flexible liner (4 ft. length)3) spring spacers (4)4) thimble (2)5) AstroCap termination cap (1)6) screws (12)7) tube of Mill Pac (1)8) plated screws (8)9) screws #8 x 1/2" Drill Point, stainless steel (4)If longer runs are needed, the Regency® Direct Vent system (Flex)# 946-516 includes all the parts needed to install the P42 with amaximum 10' run.1) 6-7/8" dia. flexible liner (10 ft. length)2) 4" dia. flexible liner (10 ft. length)3) spring spacers (7)4) thimble (2)5) AstroCap termination cap (1)6) screws (12)7) tube of Mill Pac (1)8) plated screws (8)9) screws #8 x 1/2" Drill Point, stainless steel (4)Note:a) Liner sections should be continuous without any joints or seams.b) Only Flex pipe purchased from Regency ® may be used for FlexInstallations.