ZHT Ultimate Sheet Bronze Cymbals. 88% Copper, 12% Tin. Zildjian’s first-ever B12 alloy results in our most musical Sheet Bronze series yet. A higher tin content, ultra-modern crafting techniques, and extensive hammering have created a more musical sound than previously found in a Zildjian Sheet Bronze cymbal. ZHT is the only Zildjian Sheet Bronze series in a traditional finish and features popular Zildjian Cast Bronze models.