This 4 x 6-5 8 restriction disk should only be used in accordance with appliance manufacture's instructions. Direct-Temp system features stainless steel inner and heavy duty galvanized steel outer walls. Heavy duty centering brackets keep inner pipe centered and chamfered edges allow for easy slide-together assembly. The free-floating inner liner allows the pipe to expand and contract under high temperature, without creating gaps or stress points. The LockTab(r) is a unique design that allows for 360° rotation while securely locking the sections of pipe together with just a push of the tab.Siliconozed fiberglass seal LockTab security Pipe rotates easily to align system components No sealant required High efficiency performanceFinish: Galvanized Fuel Type: Gas Inner Wall: 304 Stainless Steel Inside Diameter: 4-1 2 Joint Connection Overlap: 1-5 8 Joint Connection Type: Twist-Lock standard on all diameters Material: Galvanized Steel Outer Wall: Heavy duty galvanized steel Outside Diameter: 5-1 4 Pipe Class: Direct Vent Pipe Inside Diameter: 4 x 6-5 8 Pipe Shape: Round UL Listed: Yes Vent Construction: Double Wall
