Sinocron HS: reactive dyes contain over two chromophoric and auxochromic groups. They have excellent exhaustion, high build-up in deep shades, high fixation rate, good solubility and low dye residue. They can solve the following problems while dyeing extra deep shades: excessive dye use or effluent load, bad reproducibility, difficulty to reach the very deep shades. They are suitable for exhaust dyeing process for all cellulosic fibers. This series of dyes is a very good combination for high chlorinated water fastness.