Ultra Yield 35.5% ZINC-GRANULAR with Sulfur is derived from zinc sulfate monohydrate and is ideal for use in blended fertilizers and for direct field application. Its uniform particle size of -5 +8 mesh blends evenly into your fertilizer mixes and does not segregate. With zinc content of 35.5%, 2.8 lbs. of product are required for 1 lb. of Zinc (Zn).