This is the first and original patented chimney flashing kit to hit the market (1992). UniFlash quickly became the standard from which many out there try to duplicate. Each kit comprises all the components needed to flash in a single-flue chimney. For double-flue, use 2 kits. Designed by professional roofers, our kits enjoy a 100% satisfaction rating since 1993. Don't get fooled by the dozens of profiteers selling metal-in-a-box, make your flashing experience a worry-free one.