F-Microtracers are a uniform steel grit and FD&C Food Dye coated product.These particles are Magnetically Retrievable with a guaranteed particle count of between 22,000 to 32,000 particles per gram. Many colors available. Microgrits: Corn Cob Grit colored particles of relatively uniform size identifiable visually in mash feeds or in pellets when broken. Six primary colors available. Selenium: We manufacture several selenium containing products on carriers such as sand or iron powders. Carrier and selenium content can be set to our customers specifications.