These diamond grinding disks are flexible and versatile. One mandrel and eight disks are included. Available in Course, Medium, Fine and Extra Fine grit. - Flexible and versatile - For forming crown edges - For reducing crown borders to correct size before porcelain firing - For constructing and shaping of acrylic and ceramic surfaces - For infinitely variable comparison of boundary positions from metal to blending - For perfect finishing of the interdental area with bridges - Ideal RPM is 8,000-10,000 - Not to be used as a separating disc