Glass Gasket 58 Horizontal Terminations 22 Glass Door 58 Flex Vent 4" x 6-7/8" 22 Glass Replacement 58 Horizontal terminations 23 General Vent Maintenance 58 Rigid Pipe 4" x 6-5/8" 23 Valve assembly Replacement 59 Horizontal Terminations Rigid Pipe 4" x 6-5/8" Vertical terminations Rigid Pipe 4