Size Arbor Grit Maxrpm Type 4? 5/8? 36# 40# 60# 80# 120# 15300 T27 4-1/2? 7/8? 36# 40# 60# 80# 120# 13300 T27 7? 7/8? 36# 40# 60# 80# 120# 8600 T27 Characteristics: Premium zirconia and ceramin grain on a nylon back,flat design? Fast initial cut rate,smooth cutting action,excellent finish Trimmed edge,nylon wears away with abrasive- for longer life. Suitable for angle grinder