What is it: A six-pack of PMD Personal Microderm replacement discs. It includes two small and four large discs in the black coarse level-for those who seek the highest level of exfoliation. Who is it for: Ideal for those who want smooth, even-toned skin. Why is it different: These aluminum oxide crystal discs allow the handheld device to operate by smoothing away dead skin cells. How do I use it: Securely place disc on PMD Personal Microderm Device (not included). Black coarse discs are for use on the body only-not the face. They're specifically recommended for use on the hands and feet. From PMD Personal Microderm.