Fine Grit 20/40 Blast Media - 10 LBS Bag;Low free silica less than 0.1% compared to sand at up to 99% free silica;Utilized for new construction, light paint and rust removal and special maintenance applications;Fast Cutting, Uniform density, Consistent gradation, A 100% recycled, green product;Harscos BLACK BEAUTY blasting abrasive has been number one in the industry for nearly 80 years.