Use for concentric vertical terminations. Includes co-linear adapter and 2 Locking Clamps. Black or terra-cotta cap. UV resistant. No storm collar required when installed with factory PolyPro flashing. PolyPro is a polypropylene vent pipe for use with ANSI Category II and IV gas-burning appliances, including high efficiency water heaters, condensing boilers and warm air furnaces.