C2 Guard FusionC2 Guard Fusion is an innovative combination of 65% C2 Guard with 35% polyurethane. In addition to dropping into the wood like C2 Guard does, it also forms a thin, low luster sheen layer on top of the wood. This means the surface of the wood has increased abrasion resistance and additional UV protection. Its ideal for horizontal surfaces you walk on such as decks. This is a fantastic product for preserving decks and porches.