This set of 5/8" radial discs contains 12 each of all 7 grits, plus a 3/32" and a 1/8" mandrel for a total of 86 pieces in all. SUNBURST® Radial Discs are the “ absolute best” for finishing and polishing hard-to-access areas without removing detail or causing flat spots. The sharp, clean, specially treated ceramic abrasive grain embedded throughout their thin flexible bristles enables them to work faster and last longer than rubber wheels, brushes, buffs, and conventional sanders. SUNBURST Radial Discs generate minimal dust and heat and eliminate the need for polishing compound. Ideal for finishing, smoothing and high-luster polishing of all precious, semi-precious and non-precious metals, acrylics and ceramics. Recommended operating speeds for most applications is 3,000-18,000 RPM (5,000 RPM for woodworking). Lower speeds allow a softer touch, greater flexibility, and more subtle results. Higher speeds provide more aggressive material removal. Using the tips of the bristles with light pressure maximizes disc life. Color coded for easy grit identification.