ThreeBond 6731, set of 3 [Price reduced for disposal] New and unused. This is an antibacterial and photocatalytic agent that combines photocatalysis using titanium oxide with "silver," which has long been recognized as an antibacterial substance. The photocatalytic action of titanium oxide decomposes harmful substances floating in the room into harmless carbon dioxide and water, and also provides the antibacterial effects of silver.