Use for concentric horizontal terminations. Includes white wall plate, 2 Locking Clamps, white firestop, and co-linear adapter. White Termination with Bird Guard Screen. UV resistant. Inner plate is 8 5/8” (220mm) square, outer plate is 9 7/16” (240mm) square for all flue sizes. 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.